Biomedical subjects

F S Messiha

Publications and source records attributed to F S Messiha.

184 records · Page 11Linked to original sources

PubMedDate not supplied

Subcellular alcohol and aldehyde-dehydrogenases in the genital system of the female rat.

Selected rat endocrine tissue, i.e., ovary, uterus and vagina were fractionated into nuclear (NC), mitochondrial (MT), and into their cytoplasmic components for the measurement of alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) in infantile and in adult female rats. The genital organs studied possessed ALDH in all subcellular fractions isolated with exception of MT-preparation of the vaginal tissue of adult rats. Measurable ADH was determined in ovarian NC fraction. Increased specific activity of ALDH as a function of age was noted in MT and CT preparations of the uterus. Kinetic studies performed on ALDH indicate a similar Vmax for all ovarian fractions of infantile and adult female rats. The NC preparation of the uterus showed higher Vmax than the remainder of the subcellular fractions studied. The apparent Km was also determined for ALDH in various genital tissues fractionated and compared to the corresponding subcellular component of the liver. The Vmax of MT and CT-ALDH of major reproductive tissues of infantile rats studied accounted for at least 30% to 50% and for 10% to 25% of that of hepatic CT-ALDH, respectively. This difference was further reduced in adult rats. The results indicate the presence of NAD-dependent ALDH in various subcellular fractions of the female genital system which may be important in the gonadal metabolic detoxification of ethanol derived acetaldehyde.

Age Factors↗

PubMedDate not supplied

Properties and regional distribution of ocular aldehyde dehydrogenase in the rat.

The rat eye possesses cytoplasmic aldehyde dehydrogenase (ALDH) activity. The enzyme is present in whole eye, in ocular fluids and is distributed in specific ocular regions. The specific activity of cornea ALDH was the highest among 6 regions studied. The ciliary body and iris combined displayed second largest activity followed by even distribution of ALDH in the retina, the sclera and the surrounding connective tissue. The cloroid and lens did not show measurable ALDH activity. The kinetics property of cornea-ALDH indicate high Vmax. In vitro addition of equal protein concentration of individual ocular regional preparations to the cornea decreased specific activity of cornea-ALDH suggesting of protein interaction and/or substrate competition phenomenon. Short-term oral administration of Vitamin A resulted in statistically insignificant increase of whole ocular tissue ALDH from controls as contrasted with inhibition of ALDH in the ocular fluid by similar short-term oral administration of disulfiram.

Acetaldehyde↗

PubMedDate not supplied

Gender and propranolol-ethanol interaction.

The in vitro effect of propranolol, a beta-receptor blocking agent, on specific activity of hepatic alcohol dehydrogenase (L-ADH) and aldehyde dehydrogenase (L-ALDH) was studied in the male and in the female rat. The presence of propranolol, in the dose range of 3 x 10(-4) M to 10(-3) M concentration in the reaction mixture noncompetitively inhibited female but not male L-ADH. Conversely, significant enhancement of mitochondrial but not cytoplasmic L-ALDH occurred in the presence of propranolol, between 10(-3) M and 10(-5) M concentration, in both sexes. The alteration of hepatic ethanol and acetaldehyde metabolizing enzymes by propranolol suggest both gender difference and possible contraindication of use of this drug in alcoholic patients.

Acetaldehyde↗

PubMedDate not supplied

Metabolic aspects of fetal alcohol syndrome.

A 10% ethanol (ET) solution was the only drinking fluid available for 60 days prior to and during pregnancy which was continued until neonatal rats were weaned. The 18 day old fetus and its liver weight of ET drinking rats were significantly decreased from water drinking controls. Liver and body weights of 14 and 21 day old neonates of both sexes were markedly decreased from controls as a consequence of ET intake. Hepatic cytosolic aldehyde dehydrogenase (ALDH) of 14 day old neonates maintained on ET was increased from water controls without a concomitant change in specific activities of mitochondrial ALDH or or liver alcohol dehydrogenase (ADH). This is contrasted with decreases in hepatic mitochondrial ALDH in 21 day old neonate of both sexes as a function of maternal ET feeding. The postnatal development of L-ALDH activity of offspring of ET-fed rats was less than that of water controls. A transient increase in liver ADH from respective controls was measured in the 21 day old males but not in females of corresponding age. The results suggest that certain metabolic changes in hepatic ET and acetaldehyde metabolism may occur in fetal alcohol syndrome. This may conceivably contribute to one of the mechanism(s) underlying the adverse reaction towards ET and to the susceptibility of the newborn of alcoholic subjects to other related CNS depressants.

Acetaldehyde↗