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345. Effect of estrogen, progesterone and centchroman on the monoamine oxidase activity of mouse pituitary
883
Abstracls control values was attained. A further experimental state of P dominance was produced in guinea-pigs by daily in-
observed
when
simultaneously.
progesterone Progeslcrone
plus cslrogcn alone
or
w;~s
Inf’usCd
a>hoclalcd
wilh
jections of P (2 mg) and Ez (0. I pg) for IO days. This was followed by a prominent uterine weight gain (2-fold) but
estrogen applied morning of either
the NA content was highly reduced (50”~ Possible physiological changes in uterine neurotransmitter levels were studied during the guinea-pig estrous cycle. The estrous phase (day l-2. eslrogen dominated) was compared IO the diestrous phase (day 9- I I. progesterone dominated). The uterine weight was highest in the estrous phase. but NA content highest in the diatrous phase. The comparison of NA (‘oit(‘~nfr(/ffot1\ in the dlestrous phase to thal in the estrous stage thus yielded even more marked differences. It IS concluded that In both rabbits and guinea-pigs a heavy P dominance Induces reductions In the amount of sympathetic transmitter. However. not only the qualitative presence of sex steroids is Important. but also quantitative progesterone-estrogen relatlonships are of relevance. The adrenerelc neurons seem to be a target for sex steroid action. separate from the rest of the uterus. as reflected by its weight.
of the plasmalic levels of LH and prevented the ovulatory peak. from appearing in the afternoon PE. Thcsc (indIngs show that the two steroids considered have dill’crcnllal actions when infused In varlouh hypothalarnlc and cxlrclhypothalamic nuclei. Consequently. it IS concluded that In studies on the effects ol ovarian hormonca II 1s Important to take Into account nor only the isolated actIon of each one of them. but also their interaction on the dlvcrsc neural structures involved In the control or ovul;!llon at
343. Interrelationship of endocrine-metabolic responses to electrical stimuiatin of the hypothalamus GARG. S. K.. CHHINA. G. S. and SINGH. B.. &partment of Physiology. All-India Institute of Medical Sciences. New Delhi-l 10016. India The modulating effects of different localized areas of the hypothalamus on various endocrine as well as metabolic functions is well recogmzed. However. the endocrine -metabolic interrelationships which are accompanied by the hypothalamic activation have noI been explored so far. In male rhesus monkeys. electrical stimulation of the various hypothalamic regions were carried out through permanently implanted electrodes. The changes in blood glucose @I). serum free fatty acid (FFA). triglycerides (TG). cholesterol (Chl). serum growth hormone (GH). insulin (IRI) and plasma cortisol (C) were determmed on electrical stimulation of the hypothalamic regtons. Lateral hypothalamic area (LHAI stimulation produced a significant increase in IRI. GH. C. gl and FFA. Ventromedial hypolhalamic (VMH) stimulation reduced IRI and gl but increased GH. C and FFA levels significantly. Cholesterol and TG were unaflected. The responses obtained from the preoptic area resembled that ol VMH. The posterior hypothalamus and mamillary body showed trends which were common IO both LHA and VMH. Thus the responses of LHA and VMH were Interrelated In affecting IRI and gl. directed to maintain g!ucose homeostasls.
344. Elk& of microinjection of progesterone and estrogen in the ralie in the plasmatic level of LH ALESSIO. M. L. M.. WANDSCHEER. D. E. and LADOSKY. W.. Department of Physiology and Pharmacology. Universidade Federal de Pernambuco. Retire 50.000. Brazil Microinjection of progesterone in the pre-optic area during the morning of either D2 or PE Inhibited the ovulatory peak ol LH from appearing in the PE afternoon. When progesterone plus estrogen were used. the inhibition of the surge of LH was observed only If the microinjection was applied during the morning ol D2. Microinjection of progesterone in the medial basal hypothalamus (MBH) at D2 produced an advance of the ovulatory peak by 24 h. This effect was not observed when progesterone and estrogen were infused simultaneously: progesterone injected in the MBH during the morning of PE significantly increased the release of LH during the afternoon. This effect IS also
the nuclei Dorsalis Rall’c during the D2 or PE induced a hignllicanl dccrca*c
in
every day or the ovulatory
cycle.
345. Elfect of estrogen. progesterone and centchroman on the monoamine oxidase activity of moose pituitary MEHROTHA. P. K. and SRIVASIAVA. K.. Divismn ol Endocrinology. Central Drug Rcbearch Institute. Lucknow. India Biogenic amines play a vilal role in the control of gonadotrophin secretion;release. Steroidal hormones. VII. estrogen and progesterone. are believed to exert their acllon hy a reedback regulatory mechanism on thoc monoamlncs. which in turn inhibits the gonadotrophlc activny of ~IIUItary. Monoamine oxidase (MAO) activity IS consldercd ;,Y a useful Index of pituitary lunctlonmg. Eslradioldlpropionate I I pg:‘mouse). progesterone (I mgmousc) and Centchroman (0.25 mg:mousel were admInistered to adult ovariectomized mice. MAO activity was mcasurcd by the method ol Krail (1965) and expressed In unlts,O.I ml of pituitary homogenate. II was observed that estrogen dccreased the MAO level significantly Icontrol. 0.172 f 0.006: treated. 0.0693 + 0.01). Progesterone al\o lowered the activity (0.061 f 0.001). Centchroman. on the contrary. markedly raised the enzymlc level (0.561 + 0.10). The results Indicate that the pituitary threshold Car stcroldal molecules like estrogen and progesterone IS dlffercnt from that or nonsteroidal estrogens such as Ccntchroman.
346. Control of monoaminergic function by adrenal cortical steroids PARVEL. H.. RAZA-BUKHARI. A.. VI%.II’RA. A. and PARVEZ. S.. University of Paris XI. Ncuropharmacology Unit. Bit 440-PC-013. 91405 Orsay. France Our previous studies Indicate that the normal lebel of clrculating corticolds serves as a rate Inn~ting factor t”or the activity of monoamlne melabollzlng enzymes In the adult as well as in the fetus. The present study show5 the Influence of selective monoamine oxldase inhlbltors upon plasma and adrenal corticoslcrone concentration In adult rats. Inhibition of monoamine oxidase activity by admInIsIration of clorgyline results In marked and signllicant Increases in plasma and adrenal corticostcrone. The mtcnslty of Increase in cortrcosterone conlent IS directly proportlonal to the degree of inhibitlon of the ewyme monoamine oxidase. Similar treatment with another selcct~ve Inhibitor of monoamine oxldase. deprinil. also results in mcreased corticosterone concentrations of the periphery. The chronic treatment of clorgyline and deprinil in lower doses but for a duration of I week also Increases blood and adrenal corticosterone content. The results pro~lde ~VIdence that the processes or monoamine metabolism by enzyme monoamine oxidase and peripheral cortlcosterone are directly interrelated. Any possible mediation of the above effects by selective monoamine oxidase Inhibitors through the media of peripheral and central monoamln& have been investigated.
Abstracls control values was attained. A further experimental state of P dominance was produced in guinea-pigs by daily in-
observed
when
simultaneously.
progesterone Progeslcrone
plus cslrogcn alone
or
w;~s
Inf’usCd
a>hoclalcd
wilh
jections of P (2 mg) and Ez (0. I pg) for IO days. This was followed by a prominent uterine weight gain (2-fold) but
estrogen applied morning of either
the NA content was highly reduced (50”~ Possible physiological changes in uterine neurotransmitter levels were studied during the guinea-pig estrous cycle. The estrous phase (day l-2. eslrogen dominated) was compared IO the diestrous phase (day 9- I I. progesterone dominated). The uterine weight was highest in the estrous phase. but NA content highest in the diatrous phase. The comparison of NA (‘oit(‘~nfr(/ffot1\ in the dlestrous phase to thal in the estrous stage thus yielded even more marked differences. It IS concluded that In both rabbits and guinea-pigs a heavy P dominance Induces reductions In the amount of sympathetic transmitter. However. not only the qualitative presence of sex steroids is Important. but also quantitative progesterone-estrogen relatlonships are of relevance. The adrenerelc neurons seem to be a target for sex steroid action. separate from the rest of the uterus. as reflected by its weight.
of the plasmalic levels of LH and prevented the ovulatory peak. from appearing in the afternoon PE. Thcsc (indIngs show that the two steroids considered have dill’crcnllal actions when infused In varlouh hypothalarnlc and cxlrclhypothalamic nuclei. Consequently. it IS concluded that In studies on the effects ol ovarian hormonca II 1s Important to take Into account nor only the isolated actIon of each one of them. but also their interaction on the dlvcrsc neural structures involved In the control or ovul;!llon at
343. Interrelationship of endocrine-metabolic responses to electrical stimuiatin of the hypothalamus GARG. S. K.. CHHINA. G. S. and SINGH. B.. &partment of Physiology. All-India Institute of Medical Sciences. New Delhi-l 10016. India The modulating effects of different localized areas of the hypothalamus on various endocrine as well as metabolic functions is well recogmzed. However. the endocrine -metabolic interrelationships which are accompanied by the hypothalamic activation have noI been explored so far. In male rhesus monkeys. electrical stimulation of the various hypothalamic regions were carried out through permanently implanted electrodes. The changes in blood glucose @I). serum free fatty acid (FFA). triglycerides (TG). cholesterol (Chl). serum growth hormone (GH). insulin (IRI) and plasma cortisol (C) were determmed on electrical stimulation of the hypothalamic regtons. Lateral hypothalamic area (LHAI stimulation produced a significant increase in IRI. GH. C. gl and FFA. Ventromedial hypolhalamic (VMH) stimulation reduced IRI and gl but increased GH. C and FFA levels significantly. Cholesterol and TG were unaflected. The responses obtained from the preoptic area resembled that ol VMH. The posterior hypothalamus and mamillary body showed trends which were common IO both LHA and VMH. Thus the responses of LHA and VMH were Interrelated In affecting IRI and gl. directed to maintain g!ucose homeostasls.
344. Elk& of microinjection of progesterone and estrogen in the ralie in the plasmatic level of LH ALESSIO. M. L. M.. WANDSCHEER. D. E. and LADOSKY. W.. Department of Physiology and Pharmacology. Universidade Federal de Pernambuco. Retire 50.000. Brazil Microinjection of progesterone in the pre-optic area during the morning of either D2 or PE Inhibited the ovulatory peak ol LH from appearing in the PE afternoon. When progesterone plus estrogen were used. the inhibition of the surge of LH was observed only If the microinjection was applied during the morning ol D2. Microinjection of progesterone in the medial basal hypothalamus (MBH) at D2 produced an advance of the ovulatory peak by 24 h. This effect was not observed when progesterone and estrogen were infused simultaneously: progesterone injected in the MBH during the morning of PE significantly increased the release of LH during the afternoon. This effect IS also
the nuclei Dorsalis Rall’c during the D2 or PE induced a hignllicanl dccrca*c
in
every day or the ovulatory
cycle.
345. Elfect of estrogen. progesterone and centchroman on the monoamine oxidase activity of moose pituitary MEHROTHA. P. K. and SRIVASIAVA. K.. Divismn ol Endocrinology. Central Drug Rcbearch Institute. Lucknow. India Biogenic amines play a vilal role in the control of gonadotrophin secretion;release. Steroidal hormones. VII. estrogen and progesterone. are believed to exert their acllon hy a reedback regulatory mechanism on thoc monoamlncs. which in turn inhibits the gonadotrophlc activny of ~IIUItary. Monoamine oxidase (MAO) activity IS consldercd ;,Y a useful Index of pituitary lunctlonmg. Eslradioldlpropionate I I pg:‘mouse). progesterone (I mgmousc) and Centchroman (0.25 mg:mousel were admInistered to adult ovariectomized mice. MAO activity was mcasurcd by the method ol Krail (1965) and expressed In unlts,O.I ml of pituitary homogenate. II was observed that estrogen dccreased the MAO level significantly Icontrol. 0.172 f 0.006: treated. 0.0693 + 0.01). Progesterone al\o lowered the activity (0.061 f 0.001). Centchroman. on the contrary. markedly raised the enzymlc level (0.561 + 0.10). The results Indicate that the pituitary threshold Car stcroldal molecules like estrogen and progesterone IS dlffercnt from that or nonsteroidal estrogens such as Ccntchroman.
346. Control of monoaminergic function by adrenal cortical steroids PARVEL. H.. RAZA-BUKHARI. A.. VI%.II’RA. A. and PARVEZ. S.. University of Paris XI. Ncuropharmacology Unit. Bit 440-PC-013. 91405 Orsay. France Our previous studies Indicate that the normal lebel of clrculating corticolds serves as a rate Inn~ting factor t”or the activity of monoamlne melabollzlng enzymes In the adult as well as in the fetus. The present study show5 the Influence of selective monoamine oxldase inhlbltors upon plasma and adrenal corticoslcrone concentration In adult rats. Inhibition of monoamine oxidase activity by admInIsIration of clorgyline results In marked and signllicant Increases in plasma and adrenal corticostcrone. The mtcnslty of Increase in cortrcosterone conlent IS directly proportlonal to the degree of inhibitlon of the ewyme monoamine oxidase. Similar treatment with another selcct~ve Inhibitor of monoamine oxldase. deprinil. also results in mcreased corticosterone concentrations of the periphery. The chronic treatment of clorgyline and deprinil in lower doses but for a duration of I week also Increases blood and adrenal corticosterone content. The results pro~lde ~VIdence that the processes or monoamine metabolism by enzyme monoamine oxidase and peripheral cortlcosterone are directly interrelated. Any possible mediation of the above effects by selective monoamine oxidase Inhibitors through the media of peripheral and central monoamln& have been investigated.