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R Marsh

Publications and source records attributed to R Marsh.

44 records · Page 3Linked to original sources

The effect of LH on cyclic AMP and progesterone in rat ovaries in vivo.

LH injected into the abdominal vein of immature female rats increased ovarian cyclec AMP levels within 1 min, and the effect lasted at least 2 hr. In PMS stimulated rats, a maximal effect on cyclic AMP levels was obtained with 5 mug of LH 10 min after injection. Significant effects were obtained with as little as 0.1 mug. The minimum effective dose required to increase ovary cyclic AMP levels in proestrus rats was 0.05 mug of LH. While 0.01 mug did not affect cyclic AMP levels, an increase in ovary progesterone was found. In other experiments, the response of cyclis AMP to LH in vivo was greater in immature ovaries than in those from animals pretreated with PMS and hCG. Small increases in cyclic AMP levels were also seen with FSH in PMS and PMS + hCG treated animals and with prostaglandin E2 and prolactin in PMS treated rats. These results parallel, to some extent, previous results found in vitro, and show that very small doses of LH can stimulate ovary cyclic AMP increases in vivo.

Animals↗

Cyclic AMP in the rat ovary: effect of endogenous LH secretion.

Cyclic AMP levels increased in ovaries from normal cycling rats on the afternoon of proestrus at the same time as the plasma LH peak occurred. Plasma progesterone was also elevated at this time. These results complement the extensive in vitro data indicating that cyclic AMP mediates the action of LH on the ovary.

Animals↗

Absence of later auditory brain stem response components, congenital horizontal nystagmus, and hypotonia in male infants.

Five male infants, all of whom showed findings of wave I or waves I and II only of the auditory brain stem response (ABR), congenital horizontal pendular nystagmus, and hypotonia of head and limbs in the early infantile period with later paresis, are discussed. Their ages ranged from 3 to 13 months at the first examination, at which time neither head control, sitting, nor walking had been attained. Follow-up studies of ABRs revealed persistent abnormalities with neither remission nor progression. In spite of these abnormalities, these infants responded well to voices and other sounds. The congenital nystagmus in each case was demonstrated by electronystagmography to have a frequency of 2 to 3 Hz. The correlation between clinical signs and ABR is uncertain as yet. However, our findings are strongly indicative of nonprogressive inborn abnormalities in the lower brain stem.

Brain Stem↗