The effects of castration on neurotransmission in the rat vas deferens

1 Responses to adrenoceptor agonist drugs and to field stimulation were examined in vasa deferentia from adult castrated or intact rats. Isometric tension was recorded in vitro from whole or transversely bisected vasa. 2 After castration vasa exhibited spontaneous contraction, noradrenaline no longer produced a 'tonic' contraction but increased the 'phasic' spontaneous activity and salbutamol inhibited spontaneous activity by a beta-adrenoceptor-mediated mechanism. 3 After castration the 'adrenergic' components of the contractile responses to field stimulation were lost whereas 'non-adrenergic' responses remained, pre-junctional inhibition of field stimulation-induced contractions by either endogenous or exogenous activation was lost but adrenergic terminals could still be demonstrated microscopically. 4 Testosterone treatment partially reversed these effects of castration. 5 The relevance of these results to the nature of neurotransmission and to the genesis of spontaneous contraction in the vas deferens is discussed.

The distribution of adrenoceptors and other drug receptors between the two ends of the rat vas deferens as revealed by selective agonists and antagonists

1. The effects of adrenoceptor agonists and other agonists on the contractile responses of the prostatic and epididymal portions of the rat isolated vas deferens to single pulse field stimulation were investigated. 2. alpha-Adrenoceptor agonists produced prejunctional alpha 2-mediated inhibition and post-junctional alpha 1-mediated potentiation of the nerve-induced responses. Guanabenz and xylazine produced mainly inhibitory effects, xylazine being 10 times less potent. Clonidine and oxymetazoline produced inhibition with similar potency to guanabenz but at higher concentrations excitatory effects were present, particularly in the epididymal portion. Phenylephrine produced only potentiation of the nerve-induced response in both portions. Potentiation of nerve-induced responses was a more sensitive and quantitative index of excitation than was direct contraction of the tissue. 3. Isoprenaline and salbutamol both gave beta 2-mediated inhibition of the nerve-induced responses in both portions of tissue. At least part of the effect was post-junctional since phenylephrine contractions were inhibited. Isoprenaline also produced a post-junctional alpha 1-mediated excitation. 4. Noradrenaline produced effects qualitatively similar to those of the other alpha-adrenoceptor agonists, inhibition and excitation predominating in the prostatic and epididymal ends respectively. 5. Morphine produced inhibition in the mouse but not in the rat vas deferens. In rat vas, however, enkephalin analogues produced pre-junctional inhibition of responses in both portions which could be partly reversed by naloxone; restoration of the adrenergic component was more complete. Rat anococcygeus showed no equivalent effect. 6. Adenosine 5'-triphosphate (ATP) inhibited nerve-induced responses in each portion with a greater effect on the prostatic portion.

N-acetyl-p-amino-phenol (paracetamol, acetaminophen) in the treatment of acute schizophrenia

The hypothesis that schizophrenia is caused by the release of prostaglandin E into the hypothalamus and may sometimes be accompanied by an elevation of temperature was examined by a clinical trial of the prostaglandin E suppressant N-acetyl-p-amino-phenol (paracetamol, acetaminophen). Ten acute schizophrenic patients were included in a double-blind, crossover trial of paracetamol and a placebo, in which each treatment was given for a week. Regular 4-hourly temperatures were recorded in all these cases and in 5 non-schizophrenic patients for comparison. The findings provided no evidence that paracetamol mitigated the symptoms of schizophrenia. The temperatures of the schizophrenics were not elevated more than those of the controls, but the number of cases used was probably too small for this finding to be conclusive.

The bacterial flora of the biliary tract and liver in man

A bacteriological study was made of 106 patients undergoing elective surgery for gallbladder disease and as a control group, of patients with a normal biliary tract but requiring laparotomy for gastrointestinal disease. The isolation rate of all species of bacteria from the gallbladder and common bile duct in those patients with calculi in the duct system and in those with nonfunctioning gallbladders was considerably higher than in patients with a normal biliary system. Surprisingly, the number of isolates from patients with a history of cholsecystitis or cholelithiasis was no greater than in the control group of patients.

Using modern techniques of anaerobic retrieval and culture, only a small number of anaerobes were isolated, and despite the prevalence of Bacteroides species as a normal gut inhabitant and as an opportunistic pathogen, this organism was not recovered from any of the sites investigated. Anaerobic species were Isolated from 8 out of the 106 liver biopsy specimens taken at a very early stage after laparotomy, but in such patients only non-specific liver changes were found by histological examinmation. In 8 patients from whom Escherichia colt or other aerobes were isolated from bile samples, at concentrates ranging from 105 to 107/cm3, the same species of organism were consistently isolated from T tube drainage samples for up to 8 or 9 days despite tetracycline therapy.

Tumor localization of 131-I-labeled antibodies by radionuclide inaging

Intravenous injections of 131-I-labeled anti-EL4 lymphoma antibodies showed progressive localization of radioactivity in EL4 transplants but not in B16 melanoma in mice carrying both tumors. Normal rabbit globulin labeled with 131-I did not localize in either tumor and cleared more slowly from the internal organs. Metastatic localization of intravenous 131-I-labeled anti-tumor antibodies was also observed in 2 cancer patients.

Polyarteritis nodosa. Cases

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