A compartmental model is presented to account for transient and steady-state changes in blood glucose concentration which result from transit through the forearm and hand in man. This model permits the inter-conversion of arterial and venous data and the derivation of arterial equivalent total body glucose models from venous data. Data were obtained from subjects in the basal state following a pulse injection of [1-14C]glucose tracer. An artery, an antecubital vein, and a dorsal vein of a heated hand (68 degrees C environment) were sampled. Blood transit time is shorter 0.3 vs. 1.0 min) and irreversible glucose loss is reduced (1.9 vs. 2.9%) in the heated hand preparation when compared to the antecubital vein preparation. Because of the smaller correction required and the smaller variation among individuals when heated hand rather than antecubital vein data are obtained, we suggest that for analysis of whole-body kinetics such data should be used along with the compartmental model correction when arterial data cannot be obtained.
The mechanisms underlying the frequent association of nausea and vomiting with elevations of plasma vasopressin(PAVP) were studied in man and rat. After oral water loads (N = 16), plasma osmolality fell in all human subjects and was associated with a decline in PAVP in 14 asymptomatic human subjects. In 2 human subjects, nausea occurred and was associated with increases in PAVP, without changes in blood pressure. During ethanol infusion (N = 28), PAVP was suppressed unless nausea supervened. In 4 nauseated human subjects, PAVP escaped from ethanol inhibition and rose to levels 10 times basal, despite the absence of hemodynamic changes. Apomorphine, a potent dopamine agonist and emetic agent, was administered to human volunteers in doses of 7 to 24 microgram/kg. There was no increase in PAVP in 3 human subjects who remained asymptomatic (7 to 16 microgram/kg). Ten human subjects experienced nausea after 16 microgram/kg, which was followed shortly by marked increases in PAVP. Emesis occurred in 5 human subjects given 16 to 24 microgram/kg, and was followed by PAVP levels similar to those seen with nausea alone. In 7 human subjects from the nausea group, the repeat study (16 microgram/kg) after pretreatment with dopamine antagonist (haloperidol, N = 4; fluphenazine, N = 3) resulted in complete blockage of apomorphine-induced AVP release. In rats, which lack an emetic reflex, apomorphine doses of 200 microgram/kg induced only slight increases in PAVP when compared to the response to 16 microgram/kg in man. These studies indicate that stimulation of the emetic reflex results in AVP-release in man. Nausea-mediated AVP release supervenes over concomitant osmolar or pharmacologic (ethanol) inhibition.
RLN is more common than previously reported, but in our series, graft loss because of RLN was rare. Aggressive use of allograft biopsies and morphologic evaluation with IF and EM are important factors in the diagnosis of RLN. The impact of new immunosuppressive agents on the incidence of RLN remains to be seen.
We have identified QOL issues that have been previously underemphasized in transplant recipients. These findings open new areas of research to further explore and define these issues. They provide new opportunities for interventions to address factors adversely impacting QOL and to develop strategies to improve QOL in these patients. Clinicians should actively solicit information about adverse effects of medications, particularly information about sexual and relationship issues, when evaluating renal recipients. These issues should be taken into account when making therapeutic decisions.
The effect of age on the hypothalamic-hypophyseal-renal axis in normal man was determined by assaying plasma arginine vasopressin (AVP) responses to inhibitory and to secretory stimuli. Nine young (21-49 years) and 13 old (54-92 years) subjects received IV ethanol (375 mg/m2 per min). AVP levels fell progressively during the infusion in the young group, but fell for only 30 min in the old group and then rose paradoxically despite the continuing increase in blood ethanol. Eight young (22-48 years) and 8 old (52-66 years) men were provided identical osmolal loads by a 2-hour IV infusion of 3% NaCl at 0.1 ml/kg per min. Serum AVP rose 2.5 times the baseline in the young and 4.5 times the baseline in the old men despite identical free water clearances. Osmoreceptor sensitivity (the slope of AVP on osmolality) was greater in the old subjects. The heightened sensitivity to hyperosomolality helps examine the paradoxical response to ethanol, since osmolality increased during that time. This increased AVP response may severe to compensate for the reduced renal ability to conserve salt and water in aging man.
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