On the cause of the hypertrophy of the surviving ovary after semispaying (albino rat) and on the number of ova in it

Abstract

Resuinen por el autor, Hayato Arai.Instituto Wistar dc rlnatomia y Biologia.Sobre la causa dc la hipcrtrofia del ovario superviviente despues de la ablacih del otro ovario (rata albina), y sobre el nfiinero de 6vulos en 41 contenidos.Trandntinn by Jme T' Noniiloa Corncll Medical Collegc, N m Y a~k

The effects of vagotomy on compensatory ovarian hypertrophy and follicular activation after unilateral ovariectomy

“…Removal of one ovary from a cycling rat results in a n increase in the number of antral follicles [follicular activation (FA)] and a n increase in ovarian weight [compensatory ovarian hypertrophy (COH)] (Hatai, 1913;Arai, 1920). Twice the normal number of ova are produced by the remaining ovary in the next cycle (Peppler and Greenwald, 1970).…”

Less Severe Ovarian Atrophy in Hypophysectomized Hemiovariectomized Rats than in Hypophysectomized Animals with Two Ovaries

“…2 weeks following hypophysectomy + uni lateral OVX the weight loss of the ovary is significantly less than that in HYPOX rats having two ovaries. Present data together with previous findings suggest that a neural pathway be tween the ovaries and the CNS may be involved in the mechanism of compensatory ovarian hypertrophy following removal of one ovary.Removal of one of the ovaries is followed by a compensatory growth of the remaining gland [1,13]. It is widely accepted that this compensatory phenomenon may be due to in creased gonadotrophic hormone secretion in duced by the specific tissue loss and as a con sequence of it, by decreased blood steroid hormone levels.…”

The number of oocytes and the rate of atresia in unilaterally ovariectomized mice up to 8 months after surgery

“…Secondly the weight of the remaining ovary (or fragment of ovary: Mandi, Zuckerman & Patterson, 1952) gradually increases after surgery (compensatory hypertrophy) and may attain the combined weights of two ovaries in controls. This ovarian weight gain probably results largely from the increased number of corpora lutea formed following compensatory ovulation (Arai, 1920;McLaren, 1966), although preovulatory follicles may also make a contribution.…”

“…There have been numerous studies on the effects of unilateral ovariectomy in a variety of species (mouse: Jones & Krohn, 1960; Biggers, Finn & McLaren, 1962a, b;McLaren, 1966;rat: Arai, 1920; Mandi & Zuckerman, 1951;Peppier & Greenwald, 1970a, b;hamster: Chatterjee & Greenwald, 1972;Chiras & Greenwald, 1978; guinea-pig: Hermreck & Greenwald, 1964;pig: Brinkley & Young, 1969). These studies permit certain conclusions to be drawn.…”