STUDIES ON THE EFFECT OF OVARIOTOMY AND HYPOPHYSECTOMY ON GESTATION IN SNAKES 1

The contractility of the oviduct of Chrysemys picta (the fresh-water turtle) was studied in vitro. Significant regional differences in contractile activity were observed. Contractions increased in amplitude and duration and decreased in frequency from the proximal to the distal end of the oviduct. Injections of oestradiol-17beta in vivo increased the amplitude of contractions and decreased the duration of the rest period in segments taken from the diatal end of the oviduct. In contrast, progesterone injections significantly reduced the duration of both contractile and resting periods.

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

The INFLUENCE OF OESTRADIOL-17β AND PROGESTERONE ON THE CONTRACTILITY OF THE OVIDUCT OF THE TURTLE, CHRYSEMYS PICTA, IN VITRO

Callard¹,

Hirsch²

1976

“…A problem asso¬ ciated with such an adaptation is the prevention of delivery of the foetus before development has been completed. A number of investigators have examined the ability of corpora lutea and exogenous progesterone to block parturition in livebearing snakes (Clausen, 1940;Fraenkel, Martins & Mello, 1940;Bragdon, 1951) and a viviparous lizard (Panigel, 1956). Although the results are not always in agreement, it appears that removal of the corpus luteum or ovariectomy may result in abortion or at least interfere with normal parturition and exogenous progesterone may extend normal gestation.…”

Section: Effect Of Steroids On the Fat Bodiesmentioning

confidence: 99%

“…Clausen (1940) presented evidence that snake neural lobe extracts induce parturition of viviparous snakes more effec¬ tively than similar sheep extracts. Munsick, Sawyer & van Dyke (1960) have utilized the turtle oviduct in vitro for bioassay and have shown that it is more sensitive to arginine vasotocin than to oxytocin.…”

Section: Introductionmentioning

confidence: 99%

Effect of Ovarian Steroids and Neurohypophysial Hormones on the Oviduct of the Viviparous Lizard, Klauberina Riversiana

Lapointe¹

1969

“…However, there is only scanty evidence that-by analogy with the mammals-they might also be involved in reproductive processes in lower vertebrates. The hormone content of the posterior lobe of birds changes during the egg-laying cycle (Legait, 1959;Tanaka & Nakajo, 1962) and the oviduct of birds (McKenney, Essex & Mann, 1932;Munsick, Sawyer & van Dyke, 1960;Munsick, 1965;Rzasa, & Ewy, 1968) and reptiles (Clausen, 1940;Panigel, 1956;Munsick et al 1960;LaPointe, 1964LaPointe, , 1969 responds to neurohypophysial hormones in vivo and in vitro. The aim of the present study was to investigate the effect of neurohypo¬ physial hormones on amphibian oviducts.…”

Section: Introductionmentioning

confidence: 99%

The Effect of Neurohypophysial Hormones on the Amphibian Oviduct in Vitro, With Some Remarks on the Histology of This Organ

Heller¹,

Ferreri²,

Leathers³

1970

The effect of neurohypophysial hormones has been tested in vitro on oviducts of four species of urodele and three species of anuran Amphibia. Contractile responses were obtained with all the hormones used but 8-arginine oxytocin (vasotocin) was usually most potent. The sensitivity of the oviducts varied widely from species to species; there were also pronounced seasonal differences within a species. Histological investigations yielded some information on the abundance and arrangement of muscle fibres in amphibian oviducts. A simple and sensitive (magnification up to \ m=x\ 1000) recording system for isotonic contractions is described.