A study of gastrointestinal opiate receptors: the role of the Mu receptor on gastric emptying: concise communication

Animal and in vitro experiments suggest that opiates exert their actions by interaction with possibly five different subtypes of opiate receptors, identified as mu, kappa, sigma, delta, and epsilon. As yet there is no conclusive evidence for their existence in man. Our experiments on morphine and the enkephalin analog DAMME have suggested at least two types of opiate receptors involved in gastric secretion. In this study we have used the very powerful and nonselective opiate agonist etorphine to stimulate as many of the different opiate receptors as possible. We have then attempted to block selectively the mu receptor by administering a small dose of naloxone. Etorphine delayed gastric emptying whereas naloxone alone had no effect. In combination, the inhibitory effect of etorphine on gastric emptying was incompletely prevented while the subjective effects of etorphine were completely abolished. These results may indicate that mu receptors are important in the regulation of gastric emptying, but that other (non-mu) receptors are also involved. The radionuclide study of gastric emptying, as used here, is a potentially powerful tool in physiological research on the gastrointestinal tract.

Ophthalmic psychoneurosis: natural history

The status of 18 patients presenting with ocular psychosomatic symptoms is reviewed 10 to 18 months after presentation. All the patients had been discharged after the examination and reassurance given at the initial interview. In 8 patients symptoms had completely ceased, but 10 patients retained their symptoms. Transitory, self-limiting symptoms were more commonly associated with anxiety and occurred in the younger patients. Persistent symptoms were more commonly associated with depression and occurred in the older patients. Pain of the eyes, face, and head is conspicuous in both groups.

Validation and application of nutrition education objectives

Nutrition education is more likely to be effective when nutrition and education professionals set goals in working with individuals. In an effort to assist such professionals with these goals, 24 objectives for nutrition education were identified and validated. Teachers, dietitians, and nutritionists can use these objectives in analyzing and targeting their nutrition efforts to influence behavior change in students, patients, employees, and clients. Ways to use the objectives and a process for behavior change to use with students are suggested.

Opioid peptides as neuroregulators: potential areas for the study of genetic-behavioral mechanisms

The opioid peptides have been related to behavior in both animal and human studies. Further investigation can be anticipated which could lead to the elucidation of genetic controls over enzymes which process these peptides and the receptors upon which the peptides act. The enzymes, both synthetic and degradative, can lead to the formation of different forms of the opiate peptides. Differential control of these enzymes or of the multiple forms of opiate receptors could lead to discrete changes in opiate status and subsequent behavioral changes. Conversely, genetically regulated behavioral modification could also lead secondarily to opiate changes.

Contact hypersensitivity, humoral immunity, and specific unresponsiveness can be induced in Syrian hamsters with simple haptens

Several inbred strains of Syrian hamsters have been immunized by skin painting with highly reactive haptens. Classical contact hypersensitivity has been assayed by the ear swelling response: the response is hapten-specific, exaggerated after re-immunization with the original hapten, and can be transferred adoptively to naive syngeneic hamsters with viable lymphoid cells, suggesting that contact hypersensitivity is mediated in hamsters by T lymphocytes. Moreover, skin painting with hapten induces significant serum titers of anti-hapten antibodies, indicating that antigen-specific B lymphocytes are also activated. Hamsters can be rendered unresponsive to these same haptens by conventional methods: 1) i.v. inoculation of the soluble hapten sulfonate or 2) inoculation of hapten-derivatized syngeneic lymphoid cells. Hamsters treated with these "tolerizing" maneuvers develop profound hapten-specific unresponsiveness that can be adoptively transferred to naive recipients with living lymphoid cells. "Unresponsive" animals, however, make strong anti-hapten antibody responses that rival the humoral immune responses found after skin sensitization. The data suggest that an active process is involved in the induction and maintenance of the unresponsive state, but responsibility can not be assigned firmly to putative suppressor T cells or to an antibody-mediated B suppressor modality.

Contact hypersensitivity, humoral immunity, and specific unresponsiveness can be induced in Syrian hamsters with simple haptens

Several inbred strains of Syrian hamsters have been immunized by skin painting with highly reactive haptens. Classical contact hypersensitivity has been assayed by the ear swelling response: the response is hapten-specific, exaggerated after re-immunization with the original hapten, and can be transferred adoptively to naive syngeneic hamsters with viable lymphoid cells, suggesting that contact hypersensitivity is mediated in hamsters by T lymphocytes. Moreover, skin painting with hapten induces significant serum titers of anti-hapten antibodies, indicating that antigen-specific B lymphocytes are also activated. Hamsters can be rendered unresponsive to these same haptens by conventional methods: 1) i.v. inoculation of the soluble hapten sulfonate or 2) inoculation of hapten-derivatized syngeneic lymphoid cells. Hamsters treated with these "tolerizing" maneuvers develop profound hapten-specific unresponsiveness that can be adoptively transferred to naive recipients with living lymphoid cells. "Unresponsive" animals, however, make strong anti-hapten antibody responses that rival the humoral immune responses found after skin sensitization. The data suggest that an active process is involved in the induction and maintenance of the unresponsive state, but responsibility can not be assigned firmly to putative suppressor T cells or to an antibody-mediated B suppressor modality.

Enkephalinase: selective inhibitors and partial characterization

There are at least two types of enzymes in brain, endopeptidases and aminopeptidases, which metabolize enkephalins. Evidence is presented to suggest that enkephalinase, an endopeptidase cleaving at the Gly-Phe bond, is specific for the endogenous enkephalinergic system. Selective inhibitors are described for each enzyme. These are parachloromercuriphenylsulfonic acid and puromycin in the case of aminopeptidases and various enkephalin fragments in the case of enkephalinase. Some characteristics of the two types of enzymes are described. Enkephalinase has many properties in common with the well-characterized brain angiotensin-converting enzyme. These two enzymes, however, behaved differently when tested for chloride dependence, for activity in several buffers and for susceptibility to specific inhibitors.

Studies on the frequency and pathogenesis of liver involvement in rheumatoid arthritis

A systematic prospective survey of 100 outpatients with rheumatoid arthritis revealed that 45 had biochemical evidence of liver disease. In most cases this was due to increases in total serum alkaline phosphatase (ALP) and/or gammaglutamyl transpeptidase (GGT). Examination of serum ALP isoenzyme profiles in 50 of the patients showed that the liver isoenzyme was the sole or major component in 44 patients, including many with normal total ALP levels. 18% had raised serum liver ALP together with raised GGT, suggestive of an underlying hepatobiliary lesion. No correlation could be detected between raised serum levels of liver enzymes and the age or sex of the patient, duration or severity of arthritis, and drug or alcohol history. However, there was a significant correlation between raised serum ALP and lacrimal or salivary gland dysfunction. It is suggested that immunological mechanisms may be involved in the development of hepatic abnormalities in rheumatoid arthritis.

Diminished contractile response of aortas from diabetic rabbits

We investigated the responsiveness of isolated diabetic and normal rabbit aortic strips to norepinephrine. Alloxan, 160 mg/kg, was administered intravenously 1 mo before experiments were performed. Helically cut thoracic aortic strips from diabetic and control animals were suspended side by side in the same muscle bath. The maximum contractile response to norepinephrine of diabetic strips was 68 +/- 5% of control in eight pairs of animals (P less than 0.001). This differential response was not changed by propranolol or cocaine, indicating that it is not explained by either enhanced beta receptor activity or more avid uptake of norepinephrine by nerve endings. Tyramine responses displayed the same differential, suggesting that endogenous release of norepinephrine also results in a lower response of diabetic aortic strips. Maximum responses to KCl were also markedly depressed in strips from nine diabetic rabbits (P less than 0.005). This indicates that the diabetes-induced changes occur at a stage in contraction beyond alpha-receptor activation.

Impairment of lachrymal and salivary secretion and cellular immune responses to salivary antigens in rheumatoid arthritis

During a systematic investigation of 100 unselected outpatients with rheumatoid arthritis, 58 were found to have reduced lachrymal or salivary secretion. No correlation could be detected between the presence or absence of secretory abnormalities and the age or sex of the patient, the presence of nodules or salivary duct antibody, or the occurrence of vasculitis. However, there was a significant correlation between diminished salivary of lachrymal flow and the occurrence of cellular immune responses to a protein fraction of normal human saliva, sensitisation being found in 94% of those with impairment of salivary and lachrymal secretion as compared with 33% of those without.

The clinical estimation of liver size: a comparison of techniques and an analysis of the source of error

The clinical estimation of liver size using radioisotope scintiscans as a standard of reference has been shown to be very inaccurate. The main source of error is in the location of the upper border of the liver. Physical characteristics of the patients influence this measurement.

Antagonistic effect of morphine on the positive inotropic response of ouabain on the isolated rabbit heart

The antagonistic effect of morphine on the positive inotropic response of ouabain was studied in 96 isolated rabbit hearts, using a modified Langendorff preparation. Decreased calcium (Ca) in the perfusate resulted in increased depression of peak left ventricular dP/dt by morphine (10(-4) gm/ml), and the number of beats required to reach the depression was proportionally reduced with the reduction of calcium chloride from 2.16 mM to 0.54 mM. Likewise, the positive inotropic effect of ouabain (10(-6) gm/ml) was proportionally reduced by the same reduction of calcium chloride concentration in the perfusate, but the number of beats required to reach the cardiotonic effect was proportionally increased with Ca deficiency. The opposing effects of ouabain and morphine were mutually antagonistic regardless of the order of drug administration. When the hearts had been previously exposed to morphine, ouabain stimulation was no longer beat-dependent. Following prior exposure to ouabain, the beat-dependency of morphine depression on the heart also was partially antagonized. These results suggest that the level of maximal dP/dt during morphine depression or ouabain stimulation is directly related to the extracellular concentration of Ca. The number of beats required to attain the depression or stimulation is probably a reflection of the rate at which equilibrium is established between the mobile fraction of extracellular and intracellular Ca, since transmembrane movement of Ca is believed to occur during each beat. A possible common site of morphine and ouabain effect may be the cellular membrane, where ionic flux occurs.