This study investigated the effects of outlet obstruction on blood flow and high energy phosphates content in the rabbit urinary bladder. Mild bladder outlet obstruction was induced by placing a silicon ring (diameter 7 mm) around the bladder neck of each male New Zealand White rabbit (n = 7). Before and immediately after inducing obstruction, and 2 weeks later, the bladders were emptied and regional blood flow measured using laser Doppler flowmetry (LASERFLO BPM2, Vasamedics Inc., St. Paul, Minnesota). Six different areas of each bladder were measured, and the average blood flow calculated for each rabbit. Then, the animals were sacrificed, the bladder excised, and the tissue content of high energy phosphates determined by high performance liquid chromatography (HPLC). Six normal male New Zealand White rabbits served as controls. The results can be summarized as follows: (1) Before surgery, bladder blood flow was similar in all animals (16.3 ml/min/100 g); positioning the silicon ring around the bladder neck did not affect blood perfusion, two weeks after the induction of outlet obstruction, bladder blood flow was significantly decreased (4.9 ml/min/100 g). (2) There was no significant difference between control and obstructed bladders in NAD, AMP, or ADP content. However, the obstructed bladders contained significantly less phosphocreatine (12.0 vs 21.9 nmol/mg protein) and ATP (4.0 vs. 6.1 nmol/mg protein) than control bladders. In summary, this study showed that urinary bladder blood flow was reduced by outlet obstruction, and the reduction in blood flow was associated with decreased tissue high energy phosphates content.(ABSTRACT TRUNCATED AT 250 WORDS)

This report communicates our attempt to design a small animal model for the evaluation of penile erection, based on the pharmacological responses of cavernous tissues in the rat that resemble those of human subjects. Male adult Sprague-Dawley rats anesthetized with pentobarbital sodium were used in conjunction with papaverine and prostaglandin E1, two vasoactive drugs most commonly used in clinical management of impotence. Intracavernous administration of papaverine (0.05, 0.1, 0.02, 0.4 or 0.8 mg.) induced a progressive increase in intracavernous pressure that peaked at 0.4 mg. This effect was associated with visible penile erection that became conspicuous when accompanied by additional bursts of transient intracavernous pressure fluctuations. The duration of papaverine-induced increase in intracavernous pressure was significantly shortened by clonidine (15 micrograms, intracavernous). Injection of prostaglandin E1 (1, 2 or 4 micrograms) into the corpus cavernosum also elicited an elevation in intracavernous pressure, but the responses exhibited acute tachyphylaxis. By manifesting a response to papaverine and prostaglandin E1 that is similar to that in human, we conclude that the intracavernous pressure in the rat may represent a suitable index for the evaluation of penile erection in small laboratory animals.

A prospective randomized study was performed to compare the effect of acupuncture and intramuscular Avafortan injection in the treatment of renal colic. Our results showed that acupuncture is as effective in relieving renal colic as Avafortan but it had a more rapid analgesic onset (3.14 +/- 2.88 minutes versus 15.44 +/- 7.55 minutes, p less than 0.05). Of the patients in the Avafortan group 7 (43.8%) had side effects, including skin rash in 3, tachycardia in 2, drowsiness in 1 and facial flush in 1. No side effects were noted in the acupuncture group. During 2 hours of observation acupuncture and Avafortan seemed to be ineffective in promoting stone passage. However, patients receiving Avafortan treatment were more likely to have paralytic ileus. In summary, acupuncture can be a good alternative for the treatment of renal colic.

By using an ethylene glycol-induced urolithiasis model, we assessed the role of testosterone in the pathogenesis of urolithiasis. The intact and castrated male and female rats were fed with 0.5% ethylene glycol in drinking water for four weeks. The renal excretions of oxalate, citrate and other electrolytes were measured, and the stone and crystal deposit were examined microscopically. The results showed that drinking a loading of 0.5% ethylene glycol for four weeks produced hyperoxaluria in all rats, but the intact male rats excreted more urinary oxalate than any other groups of rats. The ethylene glycol-fed rats exhibited hypocitraturia except the castrated male rats. However, urolithiasis occurred in intact male but not female rats. Castration in male rats fed with ethylene glycol dramatically decreased the incidence of renal stone from 71.4% (5/7) to 14.3% (1/7). On the other hand, there was still no renal stone formed in the oophorectomized female rats which received ethylene glycol treatment. These data indicate that serum testosterone level plays a determinant role in urolithiasis formation.

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