No abstract

Sexual development is inhibited in Siberian hamsters (Phodopus sungorus) in short days (SD), and a small uterus is an obvious indicator of photo-inhibition. The small uterus in SD is presumably due to the delayed onset of estrous cycles. However, in an earlier study, the investigators reported that serum estradiol (E2) concentration was significantly higher in young females raised in SD than in long days (LD), with the highest concentrations measured in SD at 4 wk of age. These seemingly contradictory findings were investigated in the present study. First, uterine mass and body mass were measured in SD-and LD-reared hamsters from 1 to 12 wk of age. Uterine mass was significantly greater in LD than in SD by 3 wk of age and onward. Thereafter, our investigation focused on 4-wkold hamsters. Serum E2 concentrations in LD and in SD were not significantly different and there were no significant LD-SD differences in uterine estrogen receptors (ER), as measured by immunohistochemistry and quantitative real-time RT-PCR. Therefore, alternative explanations for the photoperiodic difference in uterine size in young Siberian hamsters are considered.

SUMMARY The effect of pentagastrin on oesophageal motility was studied in six subjects with idiopathic diffuse^.esophageal spasm (IDOS). Pentagastrin was administered by continuous intravenous infusion in doses of 1 ,ug/kg/h, 5 ,ug/kg/h, and 10Xtg/kg/h. Saline infusion was used as a control. No subject experienced pain during pentagastrin infusion. Two developed dysphagia and repetitive contractions with 'wet' swallows during the saline infusion and the lowest pentagastrin infusion. Contraction amplitude was increased only with 'dry' swallows during the 10,ug/kg/h infusion period. Contraction duration was increased with both'wet' and 'dry' swallows during the 1 gg/kg/h infusion, and with 'dry' swallows during the 10 pg/kg/h infusion. Propagation velocity was not altered by pentagastrin. We conclude that gastrin released physiologically by eating probably does not contribute to symptom production in IDOS. Moreover, it seems unlikely that pentagastrin, at least in these doses, can be exploited for diagnostic purposes.Idiopathic diffuse oesophageal spasm (IDOS) is a disorder characterised by dysphagia, chest pain, or both. In typical cases, manometry reveals prolonged, powerful, repetitive, and simultaneous contractions in the lower two-thirds of the oesophageal body. Although oesophageal spasm can occur as a result of a variety of underlying disorders,' the aetiology of the primary syndrome remains obscure. Eckhardt, Kruger, Holtermuller, and Ewe2 first noted that oesophageal spasm could be precipitated by pentagastrin in patients with IDOS. Hollis, Levine, and Castell3 had previously shown that similar doses of pentagastrin given to normal subjects increased the lower oesophageal sphincter pressure but did not affect motility in the oesophageal body. The observations of Eckhardt et aL.2 were confirmed by others4 5 and led to the speculation that supersensitivity to endogenous gastrin might underlie the symptoms in this disorder.6 Further, it appeared that pentagastrin administration might prove useful as a provocative test to aid in diagnosis of the syndrome in patients whose radiographic and manometric abnormalities were not clearcut. However, other investigators have found no supersensitivity to gastrin7 or supersensitivity only when gastrin is administered in pharmacological doses.5We set out to determine the effects of physiological Address for correspondence: Michael D Kaye, University of Vermont, College of Medicine, Given Building, C307, Burlington, Vermont 05405, USA Received for publication 16 October 1980 and supra-physiological doses of pentagastrin in patients with IDOS. We included in our analysis the effect of pentagastrin on propagation velocity of oesophageal contractions, an effect not previously defined. Our experiment was designed to provide relatively stable serum pentagastrin levels, to control for placebo effect, and to avoid bias. MethodsSix subjects with IDOS were studied. All had dysphagia, chest pain, or both. Prominent tertiary waves or a corkscrew appearance on barium swallow, and s...