Search PubMed⌕ Search

Biomedical subjects

D H Catlin

Publications and source records attributed to D H Catlin.

52 records · Page 3Linked to original sources
PubMed1978

Beta-endorphin is behaviorally active in rats after chronic intravenous administration.

Male Sprague-Dawley rats received 14 daily intravenous injections of saline or human beta-endorphin (2.5 mg/kg). Animals were given one-way active avoidance training on the eleventh day, and analgesia testing on the twelfth (tail-flick) and thirteenth (hot-plate) days. Beta-endorphin had no effect on the number of trials needed to reach the avoidance criterion, but significantly lengthened response latencies. Beta-endorphin had no analgesic effect in either test procedure.

Animals↗
PubMed1977

Inability of naloxone to change brain morphine levels in tolerant mice.

The effect of naloxone on brain morphine concentrations was measured in naive and morphine-dependent mice using radioimmunoassay and gas-liquid chromatography. No displacement of morphine from the brain by naloxone could be observed in naive mice acutely injected with morphine or in pellet-implanted mice at increasing intervals after removal of the morphine pellets. The suggestion of a change in affinity of opiate receptors during the development of tolerance/dependence, which had been made on the basis of the displacement of morphine by naloxone found by other workers, is thus not supported by the present results.

Animals↗
PubMed1977

Pharmacokinetics of morphine by radioimmunoassay: the influence of immunochemical factors.

Two radioimmunoassays (RIA-A and RIA-B) were used to estimate morphine equivalents (ME) in rabbit serum after i.v. administration of morphine or morphine-3-glucuronide (M-3-G). RIA-A and RIA-B differed only with respect to the particular pool of antibodies used, and both were elicited from rabbits immunized with a 2-diazomorphine-protein conjugate. In vitro inhibition studies indicated the molar ratio of M-3-G/morphine which inhibited 3H-morphine-antimorphine binding by 50% (150) was 90 and 14 for RIA-A and RIA-B, respectively. RIA-B 150 values were dependent on the final protein concentration of the incubation mixture. RIA-A and RIA-B estimates of the ME per milliliter were in agreement in serum samples obtained from rabbits after i.v. morphine 0.01 mg/kg; however, after higher doses only samples obtained in the first minutes agreed and at later times RIA-B estimates exceeded RIA-A by increasing amounts. After i.v. M-3-G (1.0 mg/kg) RIA-B estimated 20 to 25 times more ME per milliliter than RIA-A. After rapid i.v. administration of morphine (1 or 5 mg/kg) the disappearance curves obtained with RIA-B were multiphasic and contained a prolonged terminal phase with an estimated half-life of 24 hours. The higher estimates obtained with RIA-B are best explained by cross-reactions with M-3-G or other morphine metabolites. With RIA-A the mean serum morphine clearance (86 ml/min/kg) and half-life of the elimination phase (74 minutes were independent of dosage. The least complicated pharmacokinetic model which describes the disposition of morphine in the rabbit is the open two-compartment model.

Animals↗
PubMed1975

Production and characterization of antibodies to meperidine.

A mepridine-bovine serum albumin (Mep-BSA) conjugate with 15-20 moles of meperidine per mole of BSA was synthesized and characterized. Rabbits immunized with Mep-BSA produced antibodies that were assayed utilizing saturated ammonium sulfate to separate 3H-meperidine (3H-M) bound to antibody from free 3H-M. Antibody specificity was assessed by competitive inhibition studies. The nanomoles of inhibitor required to decrease the binding of 3H-M by 50% were: meperidine .046; meperidine acid, 3.2; alphaprodine, 7.8; dextromethorphan, 20; codeine, 50; and morphine 55. The sensitivity of the assay is approximately 30 ng/ml; sufficient for pharmacokinetic studies of the disposition of meperidine in man.

Animals↗
PubMedDate not supplied

Trace contamination of over-the-counter androstenedione and positive urine test results for a nandrolone metabolite.

CONTEXT: Several anabolic steroids are sold over-the-counter (OTC) in the United States, and their production is not regulated by the US Food and Drug Administration. Reports have suggested that use of these supplements can cause positive urine test results for metabolites of the prohibited steroid nandrolone. OBJECTIVES: To assess the content and purity of OTC androstenedione and to determine if androstenedione and 19-norandrostenedione administration causes positive urine test results for 19-norandrosterone, a nandrolone metabolite. DESIGN: Randomized controlled trial of androstenedione, open-label trial of 19-norandrostenedione, and mass spectrometry of androstenedione preparations, conducted between October 1998 and April 2000. SETTING: Outpatient facility of a university hospital. PARTICIPANTS: A total of 41 healthy men aged 20 to 44 years. INTERVENTION: Participants were randomly assigned to receive oral androstenedione, 100 mg/d (n = 13) or 300 mg/d (n = 11) for 7 days, or no androstenedione (n = 13); in addition, 4 patients received 10 microg of 19-norandrostenedione. MAIN OUTCOME MEASURES: Content of OTC androstenedione preparations; level of 19-norandrosterone in urine samples, determined by mass spectrometry, compared among the 3 randomized groups at day 1 and day 7, and among the participants who received 19-norandrostenedione from October 1998 to April 2000. RESULTS: All urine samples from participants treated with androstenedione contained 19-norandrosterone, while no samples from the no-androstenedione group did. Urinary concentrations were averaged for day 1 vs day 7 measurements; mean (SD) 19-norandrosterone concentrations in the 100-mg/d and 300-mg/d groups were 3.8 (2.5) ng/mL and 10.2 (6.9) ng/mL, respectively (P =. 006). The 19-norandrosterone content exceeded the cutoff for reporting positive cases (>2.0 ng/mL) in 20 of 24. The androstenedione preparation used was pure at a sensitivity of 0.1%, but at 0.001% 19-norandrostenedione was found. For the 4 participants to whom 10 microg of 19-norandrostenedione was administered, 19-norandrosterone was found in all urine samples. Of 7 brands of androstenedione analyzed at the 1% level, 1 contained no androstenedione, 1 contained 10 mg of testosterone, and 4 more contained 90% or less of the amount stated on the label. CONCLUSION: Our study suggests that trace contamination of androstenedione with 19-norandrostenedione is sufficient to cause urine test results positive for 19-norandrosterone, the standard marker for nandrolone use. Oral steroid doses as small as 10 microg are absorbed and excreted in urine. Some brands of androstenedione are grossly mislabeled. Careful analysis of androstenedione preparations is recommended in all studies of its biological effects. JAMA. 2000;284:2618-2621.

Adult↗
PubMedDate not supplied

Psychological moods and subjectively perceived behavioral and somatic changes accompanying anabolic-androgenic steroid use.

To assess physiological and psychological states accompanying anabolic-androgenic steroid use, male weight lifters 1) were interviewed regarding their physical training and the patterns and effects of any drug use; 2) completed a written physical and medical history questionnaire, a Profile of Mood States questionnaire, and the Buss-Durkee Hostility Inventory; and 3) were physically examined, including a blood sample and urinalysis. Subjects were divided into current anabolic-androgenic steroid users (N = 12), previous users (N = 14), and nonusers (N = 24). Current and previous users reported the following changes associated with anabolic-androgenic steroid use: increases in enthusiasm, aggression, and irritability; changes in insomnia, muscle size, muscle strength and density; faster recovery from workouts and injuries; and changes in libido. We were unable to confirm these interview and physical and medical history questionnaire responses using standardized and well-accepted psychological inventories. There were no significant differences among groups for any Profile of Moods factor, total mood disturbance, total Buss-Durkee Hostility Inventory score, or any subscale. For current users, there were no significant correlations between either total weekly drug dose or length of time on the current cycle of anabolic-androgenic steroids and any individual scale of the Profile of Mood States, Buss-Durkee Hostility Inventory, Profile of Mood States total mood disturbance, or composite Buss-Durkee Hostility Inventory score. Furthermore, anabolic-androgenic steroid users did not differ in their responses on these inventories from nonusers or from general population norms.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗