The Hormonal Control of the Guinea Pig Corpus Luteum During Early Pregnancy

Antonini, R.; Turner, Terry T.; Pauerstein, Carl J.

doi:10.1016/s0015-0282(16)42203-x

Cited by 32 publications

(19 citation statements)

References 15 publications

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“…This increase in oestradiol output from the ovary precedes an increase in PGF2. output from the uterus by 24 h (Blatchley et al, 1972;Earthy et al, 1975;Antonini et al, 1976). Oestradiol acting on a progesterone-primed uterus appears to be the physiological stimulus for increased PGF2.…”

Section: Discussionmentioning

confidence: 99%

The effect of caffeine on prostaglandin output from the guinea‐pig uterus

Naderali

Poyser

1994

British J Pharmacology

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1 Caffeine increased the outputs of prostaglandin F2,. (PGF2.a), PGE2 and 6-keto-PGFI, from the guinea-pig uterus on days 7 and 15 of the oestrous cycle. The effect on PGE2 output depended on the age of the animals and was absent in younger guinea-pigs (<4 months). Theophylline also stimulated the outputs of PGF2,. and 6-keto-PGFI6, but not the output of PGE2, from the day 7 guinea-pig uterus. 2 The stimulatory effects of caffeine on the outputs of PGFu, PGE2 and 6-keto-PGFI. from the guinea-pig uterus were not prevented by lack of extracellular calcium, ryanodine or ruthenium red (both inhibitors of calcium release via the ryanodine receptor), although the increase in PGFu. output tended to be slower when extracellular calcium was absent. Also, ryanodine flattened and broadened the peak of increased PGFu. release.3 The calmodulin antagonists, W-7 and trifluoperazine, had no inhibitory effect on the caffeinestimulated increases in uterine prostaglandin output. In fact, W-7 (but not trifluoperazine) greatly potentiated the action of caffeine on uterine PGF2, output, but had little or no potentiating effect on the action of caffeine on uterine PGE2 and 6-keto-PGFIc outputs.4 TMB-8, an intracellular calcium antagonist, inhibited the increase in PGF2,, output produced by caffeine without preventing the increases in outputs of PGE2 and 6-keto-PGF1I. 5 These studies suggest that caffeine stimulates uterine PGF2, synthesis and release by a mechanism dependent upon intracellular calcium, but this mechanism is not mediated by activation of any of the three well-characterized ryanodine receptors or by calmodulin. Furthermore, the increases in the synthesis and release of PGE2 and 6-keto-PGFI. in the guinea-pig uterus induced by caffeine appear to involve mechanism(s) different from that which stimulates PGF2. production.

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Section: Discussionmentioning

confidence: 99%

The effect of caffeine on prostaglandin output from the guinea‐pig uterus

Naderali

Poyser

1994

British J Pharmacology

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“…In intact guinea-pigs, oestradiol output from the ovary increases after day 10 of the cycle (Joshi et al, 1973) and this increase precedes the increase in PGF2a output from theuterusby24 h (Blatchley etal, 1972;Earthy etal, 1975;Antonini et al, 1976). In guinea-pigs, oestradiol acting on a progesteroneprimed uterus is therefore the physiological stimulus for increased synthesis of PGF2a by the endometrium.…”

Section: Introductionmentioning

confidence: 99%

Hormonal control of proteins synthesized and secreted by guinea-pig endometrium

Abdi-Dezfuli¹,

Poyser²

1993

Reproduction

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The amounts of protein synthesized and secreted (as indicated by [3H]leucine incorporation) by guinea-pig endometrium cultured for 24 h increased 2.1-fold between days 7 and 15 of the oestrous cycle. This increase did not occur if the guinea-pigs were pregnant. In ovariectomized guinea-pigs, oestradiol acting on a progesterone-primed uterus was the optimum stimulus for the maximum increase in endometrial protein synthesis and secretion. The two main proteins synthesized and secreted by day-15 guinea-pig endometrium had molecular masses of 99.8 and 192.1 kDa as determined on Sephacryl S-200HR. The production of the 99.8 kDa protein increased 5.2-fold between days 7 and 15 of the cycle. The 192.1 kDa protein was not detected in secretions produced by day 7 endometrium, and the 99.8 and 192.1 kDa proteins were not detected in secretions produced by day-15 pregnant endometrium. In ovariectomized guinea-pigs, progesterone did not stimulate the synthesis of secreted proteins of molecular masses above 77 kDa. Oestradiol stimulated the synthesis of secreted proteins with molecular masses of 87.8 and 192.1 kDa. However, oestradiol acting on a progesterone-primed uterus stimulated the synthesis of the secreted proteins with molecular masses of 99.8 and 192.1 kDa, which indicates that this combination of steroid hormones may be responsible for the increase in production of these two proteins by the day-15, nonpregnant guinea-pig endometrium. This stimulation by ovarian steroids of the synthesis and secretion of the 99.8 and 192.1 kDa proteins by the guinea-pig endometrium is apparently inhibited during early pregnancy.

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“…It may thus be that decidual tissue acts by producing both a « prolactin-like » hormone and PGE. On the other hand, in guinea-pig and woman, the onset of pregnancy is characterized by a decrease in PGE production (woman : Maathuis and Kelly, 1978 ;guinea-pig : Antonini, Turner and Pauerstein, 1976 ;Poyser and Maule-Walker, 1979 …”

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confidence: 99%