PLASMA CORTISOL LEVEL AND MAIN METABOLISM EVOLUTION IN PREGNANT EWE

PLASMA CORTISOL LEVEL AND MAIN METABOLISM EVOLUTION IN PREGNANT EWE N. Dojnă, Iulin Codrenu, Costin Budică Fculty of veterinry medicine Buchrest, Romni, dojn2001@yhoo.com. Abstrct The purpose of this reserch ws to determine the role of glucocorticoid hormones in enhncing metbolic processes chrcteristic of gesttion in ewe. In this respect group of pregnnt ewes ws monitored in terms of evolution of plsm cortisol nd metbolism during period of bout 14 weeks from the time of pregnncy dignosis. Prllel determintions were mde in control group consisting of non pregnnt ewes. It ws determined the evolution of plsm cortisol, plsm glucose, triglycerides, cholesterol, proteins, ure, uric cid, fibrinogen, cretinin, mylse, clcium, phosphorus nd mgnesium. Results relived progressively incresing of plsm cortisol concentrtions in pregnnt ewes compred with control. In prllel it ws found different evolution of determined blood prmeters by compring with control, mening different metbolic evolution of the studied prmeters in pregnnt vs. control ewes. The metbolic evolution of the blood determined prmeters in pregnnt ewe correlted to n incresed secretion of cortisol. Key words: cortisol, ewe, pregnncy, metbolism. INTRODUCTION The pregnncy sttus of mmmlin in mrked by very intensive nd vried metbolic dynmic. This metbolic dynmic is monitored by nervous system s well s endocrine system. In ddition to protecting nd crrying consecrted pregnncy hormones (e.g. progesterone, estrogen), specil plce nd role they hold other metbolic hormones, including glucocorticoid hormones (Cmpbell, 1987; Reismn şi Mtheny, 1968; Wood, 1988). MATERIAL AND METHODS To rech the objectives of this reserch the following ctivities were performed: firstly, it ws identified frm which greed the collbortion in these experiments. Then, group of pregnnt ewes (experimentl) nd nonpregnnt (control) ewes were dignosed. The experimentl nd control groups were constituted by ewes of Spnc, Krkul nd Tzige crossed 126

breed, two yers ged, second gesttion. The pregnnt ewes were dignosed using n ultrsound method (LOGIQ 100 TM PRO echogrph). This device llows the dignostic of gesttion nd the number of fetuses. The groups were cliniclly monitored for the evolution of gesttion nd helth. Both ewe groups, experimentl nd control were kept in the herd nd fed d libitum using n lph lph nd grss hy bsed forge. Blood ws smpled for period of gesttion monitoring: 14 weeks from the moment of pregnncy dignose. For blood smpling, only p.v.c. EDTA-type nticogulnt vcuutiners were used, tight locked, tht were slowly gitted for homogeniztion. Smpling ws done 14 times, t bout one week intervls, from November (from the moment when the dignostic of pregnncy ws techniclly possible) to Februry. The tubes were positioned on 45 ngle for fst velocity sedimenttion / seprtion, stored t lbortory temperture, nd trnsported in time for lbortory determintions, which were done no lter thn two hours from the moment of smple collection. Determintion of serum hydrocortisone ws done by n enzymtic method ccording to Dim Gesellschft für Dignostik. Blood biochemicl prmeters (glucose, totl lipids, cholesterol, totl protein, ure, uric cid, fibrinogen, cretinin, clcium phosphorus nd mgnesium nd mylse ctivity) were determined ccording to Mnt et l. (1976). The obtined dt were sttisticlly processed nd expressed s men ± stndrd error of men of ech nlyzed group. The differences between the obtined vlues from the two groups were sttisticlly nlyzed by pired Student t test, ccording to Tcu (1968). The differences between group were considered significnt when P < 0.05. RESULTS AND DISCUSSION The dt presented in Figure 1 show the following: men plsm cortisol concentrtions were not constnt over the considered period, ie, November 17, 2009 to Februry 23, 2010. The vlues vried between 4.39 nd 8.45 ng / ml of plsm in the experimentl group (pregnnt ewes). There is generl tendency to increse plsm levels of cortisol, both in the group of pregnnt ewes nd ewes in the control group (brren, nonpregnnt). In this respect it is found tht the cortisol levels of November, fter instlling the ltest pregnncy, were locted t round 4.45 ng / ml in the control group nd 4.39 ng / ml in the experimentl group without 127

sttistic significnt differences between groups. These vlues incresed to 4.99 ng / ml in the control group nd 4.95 ng / ml in the experimentl group in mid-december, then to 5.82 ng / ml in the control group nd 6.57 ng / ml in the experimentl group mid-jnury. In mid-februry, vlues of plsm cortisol levels were 6.60 ng / ml in the control group nd 7.55 ng / ml in the experimentl group. It ppers tht this growth hs chrcterized both the control group nd experimentl group. On the other hnd it ws found sttistic significnt difference (P < 0.05) between men plsm cortisol in the experimentl group compred with the control, strting from Jnury. This hs become distinct difference sttisticlly significnt (P < 0.01) in Februry, fter which the men plsm cortisol of the control group mounted to 6.55 ng / ml, while those in the group of pregnnt ewes vlues were 7.80 ng / ml. Incresed plsm cortisol in the group of brren ewes could be explined by the grdul cooling of the wether nd switch to mintennce in stlls, which my crete some discomfort nd stress in row, tht cn be reflected in incresed cortisol secretion (Dmjnovic, 2008). For the chrcteriztion of metbolic pthwys in pregnnt ewes, nd if this trend is relted or not with cortisol level it ws monitored the development of the blood plsm concentrtion of glucose, triglicerides, proteins, ure, uric cid, fibrinogen nd mylse. It ws lso monitored 128

blood levels of certin minerls: clcium, phosphorus nd mgnesium. Findings of metbolic pthwys of clcium, phosphorus nd mgnesium were crried out bsed on monitoring the evolution of these elements in serum. The results re presented in Tble 1. Tble 1 The evolution of the min blood biochemicl prmeters in pregnnt ewes vs. non pregnnt ewes long period of bout 14 weeks of gesttion, from the dy of pregnncy dignostic Item Vlues of reference Glucose 40 80* Totl lipids ~300 Cholesterol 60-150* Totl proteins (g/l) 58-60*** Albumins (g/l) Globulins (g/l) 42% from totl*** 58% from totl*** Ure 35 Dt of blood smpling nd the obtined vlues 17 Nov. 09 Dec. 28 Dec. 11 Jn. 26 Jn. 23 Feb. C P C P C P C P C P C P 54± 1± 98± 79± 43 39± 16 40± 12 29± 3 112± 34 420± 150 22 165± 71 69± 20 96± 25 44± 10 78± 229± 99 207± 35 68± 30± 6 38± 4 49± 12 157± 12 309± 176 2± 43 113± 15 50± 8 63± 14 40± 5 74± 140± 54 190± 109 80± 23 46± 18 43± 16 24± 20 147± 16 300± 45 154± 43 29 60± 83± 15 37± 10 87± 23 134± 17 1± 31 87± 28 40± 8 47± 16 39± 12 31 350± 134 87 145± 43 68± 77± 29 46± 12 76± 29 54 176± 39 75± 28 36± 19 41± 9 41± 10 1± 43 409± 135 9± 86 140± 54 65± 22 85± 52± 20 77± 29 152± 44 194± 52 79± 31 38± 41± 9 34± 11 1± 33 454± 143 136± 40 158± 77± 81± 20 54± 15 * Norml vlues in dult ewe, ccording to Reece, 1996. ** Norml vlues in dult ewe, ccording to Kolb, 1974. *** Norml vlues in dult ewe, ccording to Ruds, 1996. C = Group of control, non-pregnnt ewes (n = 8) P = Experimentl, pregnnt ewes (n =12) P<0,05 (sttistic processed vs. control in the sme dy) P<0,01 The evolution of blood glucose vlues in the group of pregnnt ewes were significntly higher (P <0.05) thn non-pregnnt ewes throughout the monitoring period, vrying between 112 nd 145 mg / dl of plsm, mintining reltively constnt higher n showing n increse of the metbolism of this metbolic fuel. 129

Tble 1 (continued) A similr sitution is recorded concerning the plsm totl lipids, to whom Item Uric cid Fibrinogen Cretinin Amylse Clcium Phosphorus 0,1-2* Vlues of reference 250-450** 1-2* 200-500* 4.5 6.0* Dt of blood smpling nd the obtined vlues 17 Nov. 09 Dec. 28 Dec. 11 Jn. 26 Jn. 23 Feb. C P C P C P C P C P C P ± 0.1 244± 1 1.0± 230± 76 4.0± 2 7* 2.4± 0.1 4.4± 2± 65 1.2± 0.4 300± 109 7.6± 2.1 3.0± 0.8 2.3± 1.2 4± 85 0.4± 0.2 180± 55 4.9± 1.5 2.8± 0.1 3.5± 251± 1 0.9± 180± 76 6.5± 3.2± 1.0 1.8± 0,8 386± 174 0.8± 420± 0 4.2± 2.2 1.1± 3± 200 1.5± 430± 289 6.6± 2.6 1.1± 0± 44 1.8± 0.8 350± 0 4.5± 2.2 3,2± 0,3 238± 39 2,0± 1,0 460± 3 7.0± 3.0 1.5± 200± 75 1.1± 0.2 240± 209 4.4± 1.6 3.3± 1.2 222± 1.8± 0.6 360± 0 1.5± 0.4 236± 3 2.0± 140± 90 7.5± 3.8± 2.3 2.7 C/P 1 2 1.6 2.5 1.7 2.0 1.8 2.1 1.8 2.8 1.5 2.4 2.6 2.8 Mgnesium Legend: 1.8 2.3* 1.4± 0.7 2.0± 0.4 3.2± 0.7 1.8± 0.2 23± 0.2 2.6± 1.7 3.1± 0.6 2.2± 1.0 2.5± 1.1 2.0± * Norml vlues in dult ewe, ccording to Reece, 1996. ** Norml vlues in dult ewe, ccording to Kolb, 1974. *** Norml vlues in dult ewe, ccording to Ruds, 1996. C = Group of control, non pregnnt ewes (n = 8) P = Experimentl, pregnnt ewes (n =12) P<0,05 (sttistic processed vs. control in the sme dy) 1.1 2.5± 0.9 2.1± 0.6 2.9± 1.0 1.9± 0.7 3.1± 1.6 1.6± 3,0± 1.8 2.2± 0.6 3.9± 0.9 231± 65 2.5± 1.2 260± 3 8.4± 2.2 2.9± 2.0 1.9± metbolism ws found significntly higher (P <0.05) in pregnnt ewes compred with non-pregnnt. Lipid levels rnged between 300 ± 45 nd 454 ± 143 mg / dl of plsm in pregnnt ewes nd 124 ± nd 152 ± 44 in brren ewes. The high level of lipids illustrtes their high tissue depot mobiliztion, which is due t lest in prt, to the high levels of plsm cortisol in pregnnt ewes, s just it ws relted. Pregnnt ewe plsm totl protein vlues vried between 113 ± 14 nd 165 ± 71 of plsm vs. 68± nd 100± g / L in control (P <0.01). High 130

concentrtion of plsm proteins cn be prtly ttributed to high levels of cortisol, but, given the physiologicl stte of dvnced pregnncy, probbly other fctors, mternl or fetl, such s incresed protein synthesis cpcity of the liver, could modify the metbolism of tht lrge ctegory of substnces (Reismn nd Mtheny, 1998, Lech nd Tylor, 2002). On the other hnd it should be noted tht the lbumin / globulin rtio remined reltively constnt. A specil mention must be done on serum totl proteins, which hve exceeded in pregnnt ewe twice the vlues in non-pregnnt ewes As reflection of enhnced protein ctbolism under the influence of cortisol it ws found elevted serum ure nd uric cid in pregnnt ewe group, compred with brren ewes. In pregnnt ewes, the vlues of the ure nd uric cid concentrtions were bove the ccepted physiologicl limits: 35 mg / dl ure nd 0.1-2 mg / dl uric cid. Concerning the developments of plsm fibrinogen nd cretinine in pregnnt ewes, they were not found significnt differences compred to the group of brren ewes. A similr sitution ws found in the serum mylse ctivity whose vlue did not differ significntly between the group of brren ewes nd pregnnt ewes, long the entire monitored period. With regrd to clcium metbolism, such s it ws presented, in dvnced stge of pregnncy, birth nd immeditely postprtum, metbolism of this chemicl element is experiencing very intense dynmic, clcium (nd phosphorus) showing very high turn-over. According to literture dt, glucocorticoid excess (Cushing's disese in the humn, for exmple) cuses muscle wekness, trophy nd loss of bone strength nd bone mtrix (Christinsen et l., 2007; Johnson et l., 1981). With n incresed secretion of glucocorticoids, bone formtion is reduced nd less quntity of clcium is bsorbed, but clcium is excreted in higher mount, which is reflected in the evolution of its plsm concentrtions, exceeding in some wy regulting functionl systems for its homeostsis. For these resons we strted to monitor clcium plsm concentrtions together with other minerls (phosphorus nd mgnesium). Tble 1 (continued) shows the evolution of serum clcium, phosphorus nd mgnesium levels in the group of pregnnt ewes compred to non-pregnnt ewes on the sme monitoring period, from November up to Februry. The dt nlysis presented in Tble 1 (continued) shows tht serum clcium ws significntly higher (P <0.05) for most dt we hve been done the determintions in the group of pregnnt ewes vs. non-pregnnt ewes throughout the ll monitored period. Also, the C / P rtio ws significntly 131

higher in the sme btch of pregnnt ewes compred with control. Plsm clcium concentrtion in non-pregnnt ewes rnged from 3.8 ± 2.7 nd 4.9 ± 1.4 mg / dl of plsm while in the group of pregnnt ewes, oscilltions rnged from 6.5 ± to 8.8 ± 2.0 mg / dl of plsm. The dt nlysis presents constnt rise in the concentrtion of plsm clcium in pregnnt ewes, this growing being ssocited with intensive fetl skeleton growing. Regrding phosphorus, serum phosphorus concentrtion is mintined within norml limits, but not so closed limits s those of clcium. In the young lmbs, serum phosphorus levels re 3 to 4 times higher thn in dult ewes. Also, plsm levels of phosphte shows lrge diurnl vritions with mximl vlues t night. In our mesurements, the C / P rtio ws between 1.5 nd 2.6 in brren ewes nd between 1.8 nd 2.8 in pregnnt ewes, which indictes incresed metbolism of both clcium nd phosphorus tken into ccount, which gin cn be considered s n effect of high plsm levels of cortisol, which in turn cuses high turn-over of these components. CONCLUSIONS During the period of gesttion in sheep, progressively incresing plsm cortisol occurs, which indictes involvement of this hormone in the regultion of metbolic processes, excerbted by the physiologicl stte of pregnncy. Intensifiction of metbolic processes such s protein, lipids, crbohydrte, clcium nd phosphorus metbolisms during pregnncy my be t lest in prt ttributed to incresed secretion of cortisol. REFFRENCES Cmpbell, E.A., E.A. Linton, C.D. Wolfe, P.R. Scrggs, M.T. Jones, P.J. Lowry. 1987 - Plsm corticotropin-relesing hormone concentrtions during pregnncy nd prturition. J. Clin. Endocrinol. Metb. 64:1054 1059. Chllis J.R., A.N. Brooks. 1989 - Mturtion nd ctivtion of the hypothlmic - pituitry drenl function in fetl sheep. Endocrine Reviews, Vol 10, 182-204. Christinsen, J.J., B.D. Christin, H. Clus, J.S. Christinsen, O. Schmitz, J. Weeke, J.O. Lunde Jørgensen, N. Møller. 2007 - Effects of cortisol on crbohydrte, lipid, nd protein metbolism: studies of cute cortisol withdrwl in drenocorticl filure. The Journl of Clinicl Endocrinology & Metbolism Vol. 92, No. 9, pp. 3553-3559, 2007. Dmjnovic, S., R. Stojic, N. Llic, M. Petkov, Al. Jotic, T. Isilovic, B. Popovic, D. Mcut şi I. Bozic. 2008 - Chnges in cortisol nd insulin during pregnncy in reltion to bsl metbolic rte. Endocrine Abstrcts, 16 P361. 1

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