It has been proposed that colorectal carcinogenesis is accompanied by increased mucosal cell proliferation and that the converse may also apply. To examine this thesis, the crypt cell production rate (CCPR) was measured in eight groups of rats (n = 187) that had received 1,2 dimethylhydrazine, 70% small bowel resection, supplemental dietary calcium, or a combination of these. Analysis of varian...

Proliferative activity of background and neoplastic colonie mucosa was examined following five months of weekly injec tions of 1,2-dimethylhydrazine (20 mg/kg) and one or four months of rest to determine whether previously reported changes may result from an acute or chronic effect of dimethylhydrazine and whether differences exist between stages of neoplasia. To determine whether neoplasia is ...

Following 4 weeks of s.c. injections of 1,2-dimethylhydrazine, a carcinogen that produces colon cancer in CF1 mice, an increase in the unidirectional mucosal to serosal flux and net absorption of sodium was observed in the distal colon. This increase in sodium transport was amiloride sensitive. 1,2-Dimethylhydrazine treatment had no effect on sodium transport in the distal colon of DBA/2 mice, ...

The effect of the bile acid sequestrant, colestipol hydrochloride, on the incidence of dimethylhydrazine-induced tumors of the large intestine was determined in male Swiss mice. The subcutaneous administration of dimethylhydrazine (15 mg/kg) produced tumors in approximately 89% of the animals with an average of 1.70 tumors per tumor-bearing animal. When carcinogen-treated animals received dieta...

A number of hydrazine derivatives were tested as substrates for the purified liver microsomal FAD-containing monooxygenase and the kinetic properties of the oxidation reactions were partially characterized. Only 1,l-dimethylhydrazine, l-methyl-l-phenylhydrazine, and the N-aminoheterocyclic hydrazines are oxidized as effectively as N,N-dimethylaniline, one of the best N-methylamine substrates fo...

The histogenesis and growth pattern of colon adenocarcinoma have been studied using 74 BD IX rats given 20 mg 1,2-dimethylhydrazine hydrochloride per kg, s.c., weekly from Day 11 to their 24th week and serially sacrificed with controls. Modifications in DNA synthesis activity and early tumor changes were sought on histological and radioautographic preparations of normal-appearing colon mucosa. ...

Several derivatives of 5-O-mycaminosyltylonolide substituted at C-23 have been prepared; these are 23-deoxy-23-C-methylene (3), 23-deoxy-23-C-(methoxycarbonylmethylene) (5), 23-deoxy-23-C-(ethoxycarbonylmethylene) (7), and 23-deoxy-23-C-(butoxycarbonylmethylene) (9), 23-deoxy-23-C-[(2E)-3-(ethoxycarbonyl)-2-propenylene] (11), and 23-deoxy-23-(dimethylaminoimino) (13), and 14-de(hydroxymethyl)-1...

Patients with chronic ulcerative colitis have a significantly increased risk of colorectal cancer development. This study was aimed at clarifying whether colitis promotes tumor development or not. A dose of 200 mg/kg body weight 1,2-dimethylhydrazine was given to male Wistar rats. Four weeks later, 5% acetic acid (colitis group) or 0.9% saline (control group) was administered intrarectally once...

The electrooxidation of methylhydrazine, 1,2-dirnethylhydrazine, and 1,1 -dimethylhydrazine at a platinum electrode was studied using chronopotentiometry, coulometry, and product analysis. The results show that methjJlhydrazine is oxidized in an over-all four-electron reaction to nitrogen and methanol. The oxidation of 1,2-dimethylhydvazine proceeds by an initial two-electron oxidation, followe...