Inhibition of acetaminophen hepatotoxicity by chlorpromazine in fed and fasted mice.

Acetaminophen hepatotoxicity has been shown previously to be potentiated by fasting, and the mechanism of hepatotoxicity has been correlated with depletion of reduced glutathione and the resulting elevation of cytosolic calcium. Chlorpromazine inhibited the hepatotoxicity of acetaminophen in a dose-dependent manner in fed and fasted mice. A 6 mg/kg dose of chlorpromazine prevented the acetaminophen-promoted increase in SGPT levels and prevented hepatic necrosis. Chlorpromazine did not prevent the depletion of reduced glutathione by acetaminophen in fed or fasted mice, although it did decrease the extent of reduced glutathione depletion caused by acetaminophen in fed mice from 80% depletion to 67% depletion. We propose that chlorpromazine causes a negative sensitivity modulation to calcium in hepatocytes, as evidenced by chlorpromazine preventing the acetaminophen-stimulated rise in phosphorylase a activity. We also propose that fasting potentiates acetaminophen hepatotoxicity by causing a positive sensitivity modulation to calcium in hepatocytes via the actions of glucagon.

Orbital fibroma in a horse.

An 11-year-old American Quarterhorse gelding presented for moderate periorbital swelling and exophthalmia of the left eye. The menace response, and direct and consensual pupillary light reflexes were absent in the left eye. Conjunctival hyperemia, blepharedema, a mydriatic pupil, resistance to retropulsion, and an increased intraocular pressure were present. A soft-tissue mass could be palpated in the left retrobulbar space by pressing onto the orbit over the supraorbital fossa. Incomplete surgical resection of the mass was performed and histopathologic evaluation was consistent with a fibroma. Normal pupillary light reflexes and vision returned following surgery. The mass has not recurred 14 months after surgery.

The Med-COR study: preparing high school students for health careers.

Recognizing the need for adequate representation of minorities in the health field, many professional schools initiated special recruitment efforts to attract minority students and developed programs to provide academic enrichment. Between 1971 and 1977, 480 black and Hispanic high school students from four inner-city schools in Los Angeles participated in the Med-COR Program (Medical Counseling, Organizing, and Recruiting) at the University of Southern California School of Medicine. The program was designed to increase the number of minority health professionals by offering enriched courses in the sciences and field experience in hospitals and laboratories. The positive results of a follow-up of 480 Med-COR students support the rationale that the number of minority health professionals can be increased by high school recruitment programs.

Calcium antagonism in isolated rat uterus by methylmethacrylate.

Methylmethacrylate (MMA) was evaluated for the ability to block actions of calcium in the isolated rat uterine preparation. MMA blocked receptor-mediated contraction and the phasic and tonic portions of the KCl induced contraction of the uterus. The effects of MMA could be antagonized by increasing the concentration of calcium. In the Ca++-free, K-depolarized preparation, MMA produced dose related depression of contraction.

Inhibition of carbon tetrachloride induced hepatotoxicity by dantrolene sodium.

A 50 mg/kg dose of dantrolene sodium decreased the hepatotoxicity of carbon tetrachloride in fed and fasted rats, as indicated by lower levels of SGPT following a toxic dose of carbon tetrachloride; however, the dantrolene sodium pretreatment did not inhibit the induction of lipid peroxidation by carbon tetrachloride. The dantrolene sodium did inhibit superoxide production by the hepatic endoplasmic reticulum in fasted rats. Also, the dantrolene sodium inhibited covalent binding of [14C] carbon tetrachloride to the hepatic endoplasmic reticulum in fasted rats, but not in fed rats.