Effects of Oxytocin on in vitro Ovarian Contractility During the Estrous Cycle of the Rat

Roca, Ricardo; Garófalo, E.G.; Píriz, Héctor; Martino, Idivia; Rieppi, G; Sala, Maria Matheus de

doi:10.1095/biolreprod15.4.464

Cited by 13 publications

(4 citation statements)

References 5 publications

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“…The spontaneous motility found in nearly one half of the isolated rat ovaries agrees with observations in cats (Rocerto et al 1969), rats Roca et al 1976), guinea pigs (Gimeno et al 1975), rabbits (Virutamasen et al 1976), monkeys (Virutamasen et al 1973), and humans ). The failure of some ovaries to Fig.…”

Section: Discussionsupporting

confidence: 84%

“…Oxytocin and prostaglandin F2a (PGF2a) are known to stimulate ovarian contractions (Virutamasen et al 1973(Virutamasen et al , 1976Gimeno et al 1975;Sterin-Borda et al 1976;Roca et al 1977), but a similar action of bradykinin has not been reported previously. The responses to bradykinin were very similar to those described for oxytocin (Roca et al 1976(Roca et al , 1977. However, the two peptides differed as to the stage of the cycle at which they were most effective (bradykinin, early oestrus; oxytocin, pro-oestrus) (Gimeno et al 1974;Sterin-Borda et al 1976;Roca et al 1977).…”

Section: Discussionmentioning

confidence: 66%

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The effects of bradykinin on the contractile activity of the isolated rat ovary

Smith¹,

Perks²

1984

Acta Endocrinologica

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Studies of ovarian contractility were carried out on 43 rat ovaries maintained in vitro. Eighteen ovaries showed spontaneous motility. In 65 of 155 tests (42%), synthetic bradykinin (3.75\p=n-\25.0 ng/ml saline) produced sustained increases in ovarian tone, or stimulated phasic contractions. Failure to respond was related to the stage of the oestrous cycle. Sensitivity was highest around ovulation (00.00\p=n-\04.00 h oestrus), when there were 25 responses in 26 tests, and the linear relationship between the response and the logarithm of the concentration suggested a threshod of 2.9 ng/ml saline. Sensitivity fell later in oestrus, and reached its lowest point in metoestrus (1 reponse in 20 tests). Since the plasma kinin system is activated before ovulation, and the threshold to bradykinin was within reported plasma kinin levels, it seems possible that plasma kinins are involved in contractile processes associated with ovulation.

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Section: Discussionsupporting

confidence: 84%

Section: Discussionmentioning

confidence: 66%

The effects of bradykinin on the contractile activity of the isolated rat ovary

Smith¹,

Perks²

1984

Acta Endocrinologica

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“…Ovaries from a number of mammals exhibit spontaneous rhythmic contractions both in vivo and in vitro which originate primarily from the hilar and medullary portions of the ovary (for review, see Espey, 1978). Several workers have shown that treatment with oxytocin can increase the resting tension as well as the frequency and amplitude of the contractions (rat: Gimeno, Borda, Rettori, Borda & Gimeno, 1973;Roca et al, 1976; Sterin-Borda, Borda, Gimeno & Gimeno, 1976;Roca, Garofalo, Piriz, Martino & Rieppi, 1977; guinea-pig: Gimeno et al, 1973;rabbit: Virutamasen, Smitasiri & Fuchs, 1976; monkey: Virutamasen, Wright & Wallach, 1973). Although Roca et al (1976) originally found no difference in the sensitivity to oxytocin at different stages of the oestrous cycle they, like Sterin-Borda et al (1976), subsequently (Roca et al, 1977) reported that a greater response occurred from ovaries of rats in pro-oestrus.…”

Section: Discussionmentioning

confidence: 99%

REVIEW Possible actions of gonadal oxytocin and vasopressin

Wathes¹

1984

Reproduction

105

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“…However, it is not clear whether the ovarian oxytocin is synthesized de novo in the ovary, since the mRNA for oxytocin proprehormone was not found in rat ovaries (36)(37)(38). It is possible that the ovarian oxytocin could affect the contractility of the rat ovary; indeed, this has been demonstrated in vitro (39)(40)(41)(42). Though the relationship between ovulation and contractility of follicles is not certain (43), oxytocin antiserum has been shown to reduce the number of ova released (20).…”

Section: Discussionmentioning

confidence: 99%

Ovarian and circulating levels of oxytocin and arginine vasopressin during the estrous cycle in the rat

Lee

1992

Acta Endocrinologica

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circulating levels of oxytocin and arginine vasopressin during the estrous cycle in the rat. Acta Endocrinol 1992;126:530-4. ISSN Ovarian extracts of Long-Evans rats separated using high performance liquid chromatography (HPLC) were measured by radioimmunoassays (RIAs) for the presence of oxytocin and arginine vasopressin (AVP). The results showed that the ovary contains both, and that they are indistinguishable from the respective standard synthetic peptides. During the estrous cycle, the ovarian content of oxytocin was 10-fold higher (p<0.01) in estrus than in the other phases, while AVP was 16-and 25-fold higher (p<0.01) in metestrus than in the other phases. In contrast, the plasma levels of oxytocin showed no significant difference among the various phases of the estrous cycle. However, the plasma level of AVP level was significantly higher (p<0.01) in diestrus than in other phases. The present study thus strongly supports the hypothesis that both oxytocin and AVP can be produced by the ovary itself in the rat. The possible roles of oxytocin and AVP in the reproductive cycle are discussed.Since the 1950s it has been widely recognized that oxytocin and arginine vasopressin (AVP) are secreted by the posterior pituitary gland and have an effect on the mammary glands, kidneys and uterus in mammals.However, there is strong evidence that the ovaries themselves may secrete these nonapeptides. For exam¬ ple, ovarian levels of oxytocin, vasopressin and neurophysin are higher than their respective circulating levels in cows, ewes (1, 2) and humans (3-5). In bovine ovaries, the concentration of oxytocin, vasopressin and neurophysin is higher in the corpora lutea than in the follicles (6, 7). In addition, oxytocin can be detected in the ovarian vein (8), and the oxytocin gene is expressed in bovine ovaries (9). AVP has also been demonstrated in luteal and theca cells of rat ovaries by immunocytochemical techniques (10). Circulating levels of oxytocin vary throughout the estrous cycle, being higher in the early to middle luteal phase than in other phases in cattle and sheep (11-13). Furthermore, the fact that exo¬ genous oxytocin injection prevents formation of the corpus luteum in cows (14) and also the fact that immunization with oxytocin prolongs the luteal phase in ewes (15, 16) suggest that oxytocin may be mediated by prostaglandin F2a (8, 17).It has also been reported that ovarian oxytocin secretion rate is inversely related to the preovulatory surge of prolactin (18) and that oxytocin antiserum may reduce that prolactin surge during proestrus in rats (19).Moreover, intrabursal administration of anti-oxytocin antiserum inhibits ovulation by 51% (20). Likewise, the administration of AVP blocks the LH surge (21) and inhibits ovulation, suggesting the involvement of AVP in the estrous cycle in rats (22,23). Cyclic variations in spinal cord levels, hypothalamic concentrations and expression of the genes for oxytocin and vasopressin during the estrous cycle have also been demonstrated (24)(25)(26). The purpose of t...

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Effects of Oxytocin on in vitro Ovarian Contractility During the Estrous Cycle of the Rat

Abstract: ABSTRACT

Cited by 13 publications

References 5 publications

The effects of bradykinin on the contractile activity of the isolated rat ovary

The effects of bradykinin on the contractile activity of the isolated rat ovary

REVIEW Possible actions of gonadal oxytocin and vasopressin

Ovarian and circulating levels of oxytocin and arginine vasopressin during the estrous cycle in the rat

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