Effects of Fe2+, Fe3+ and desferrioxamine on paraquat accumulation by rabbit kidney cortex slices

Effects of Fe2+, Fe3+ and desferrioxamine (DFO) on the accumulation of paraquat (PQ) into rabbit kidney cortical slices were studied. Fe3+ showed dose-dependent inhibition of PQ accumulation. Fe2+ had a more powerful stimulatory effect on the lipid peroxidation of cortical slices than Fe3+, but it did not reduce PQ accumulation. The addition of DFO made the inhibitory effect of Fe3+ on PQ accumulation more pronounced. These results suggest that Fe3+ is able to inhibit the accumulation of PQ independent of its peroxidative action, and that Fe(3+)-desferrioxamine (ferrioxamine) may serve as an antidote for the toxicity of PQ.

[Study of incidental carcinoma of the prostate. Part 1. Pathological analysis related to the clinical features]

To clarify the clinico-pathological characteristics of incidental carcinoma of the prostate, we investigated a total of 590 prostatic tissues which had been operated under the diagnosis of benign prostatic hyperplasia (BPH), including 12 whole prostatic specimens which were obtained by total cystectomy due to bladder cancer. Histological examination and estimation of the tumor volume were carried out by either a 3-mm step-section in 185 prostates obtained by open surgery, or by mounting whole specimens in 405 TUR cases. Incidental cancers were detected in 69 of the 590 patients (12%) with nearly equal numbers of stage A1 and stage A2 diseases. The age and the size of the prostate were significantly greater in the patients with cancer, compared to those without cancer. However, these parameters were not in agreement with each other. Histological analysis revealed that 46 of the 69 (67%) incidental cancers were well differentiated and nearly corresponded to Gleason's sum score of 2-4. In the analysis of the differentiation of the tumor cells and the tumor extension, nearly 80% of the 23 well differentiated cancers were manifest in a single lesion and were smaller than 0.3 cm3, whereas 90% of the 11 moderately or poorly differentiated cancers were diffusely invasive. Six of the 11 cases (55%) were larger than 0.3 cm3. The prognosis of the 16 incidental cancer patients who had survived more than 5 years after the surgery were compared with the controls. The controls were selected among the cases without incidental cancer, and matched for age and the time of operation in a 1 to 2 fashion without knowledge of their prognoses.(ABSTRACT TRUNCATED AT 250 WORDS)

Quantitative structure-activity relationship of catechol derivatives inhibiting 5-lipoxygenase

Various catechol derivatives (beta-substituted 3,4-dihydroxystyrenes, 1-substituted 3,4-dihydroxybenzenes, and 6-substituted 2,3-dihydroxynaphthalenes) were synthesized and their inhibition of 5-lipoxygenase was assayed. Their structure-activity relationships were examined quantitatively with substituent and structural parameters and regression analysis. The variations in the inhibitory activity were explained in bilinear hydrophobic parameter (log P) terms, and steric (molecular thickness) and electronic (proton nuclear magnetic resonance (1H-NMR) chemical shift of the proton adjacent to the catechol group) parameter terms. The hydrophobicity of the inhibitor molecule was important, and the optimum value of logP was about 4.3-4.6, beyond which inhibition did not increase further. A lower electron density of the aromatic ring containing the catechol group and the greater thickness of the lipophilic side chains were unfavorable to the activity. The results added a physicochemical basis for the selection of candidate compounds for developmental studies.

Practical assessment of natural heart function using echocardiography in mechanically assisted patients

Left ventricular assist systems (LVAS) can maintain the systemic circulation of patients with acute, profound heart failure. The assessment of natural heart (NH) function, however, is difficult in the clinical setting. The authors introduced a new index, heart rate-corrected ejection time/left atrial pressure (ETc/LAP) using echocardiography to evaluate NH function in 15 adult patients on the original LVAS for greater than 2 days. Bypass flow (BF) was gradually decreased according to the recovery of NH. Five patients were weaned from LVAS within 15 days, and LV function was well maintained (Group 1). Another six patients were weaned from LVAS within 21 days but died within 2 weeks (Group 2). The other four patients died on LVAS without recovery of NH (Group 3). In Group 1 patients, ejection time/pre-ejection period (ET/PEP) with LVAS assist increased continuously. In Groups 2 and 3, ET/PEP increased slowly and reached a plateau at approximately 10 days or remained low. Group 1 patients reached an ETc/LAP of 35 +/- 10 on LVAS within 7 days. Group 2 and Group 3 patient values were 18 +/- 2 (p less than 0.05) and 9 +/- 6 (p less than 0.01), respectively, on the seventh day. Based on these data, this new index provides an estimate of global NH function and a prediction of the probability of NH recovery.

Japanese quail and human acid maltase deficiency: a comparative study

A morphological study was carried out on the skeletal muscle of a mutant Japanese quail with acid maltase deficiency (AMD). The affected quails began to experience difficulty in lifting their wings about 6 weeks after hatching. Four weeks after hatching, before symptoms appeared, alpha-1, 4-glucosidase activity in skeletal muscle was decreased to less than 10% of the control level, and muscle fibers possessed many vacuoles containing periodic acid Schiff (PAS) positive material which was digested by diastase, and showed high acid phosphatase activity. Although both red and white muscles were involved, the pectoralis superficialis (PS, white) muscle was preferentially affected, showing intracytoplasmic vacuoles, variation in fiber size and fatty tissue replacement relatively early in the disease. The quails' disease closely resembled human late onset AMD in the slow clinical course, the presence of residual acid alpha-glucosidase activity and the muscle pathology. This mutant quail seems a useful model for elucidation of the muscle degeneration in human AMD (glycogen storage disease type 2).

[Transesophageal Doppler echocardiographic measurement of cardiac output using mitral anulus method]

The method of measuring cardiac output with transesophageal pulsed Doppler two-dimensional echocardiography was developed and validated by comparison with the thermodilution technique in 65 adult patients. With the use of transesophageal four-chamber view, the Doppler sample volume was placed in the center of the mitral ring and the mitral flow velocity-time integral was obtained through planimetric measurements of the mitral flow velocity curve. The diameter of the mitral valve anulus was measured at the time of peak rapid filling flow velocity, and the cross-sectional area of the mitral valve anulus was calculated, assuming a circular shape. Doppler-determined cardiac output was calculated by using the following formula: Cardiac output [1.min-1] = pi (D [cm] /2)2.MFVI [cm].heart rate [bpm].10(-3), where MFVI is mitral flow velocity-time integral, and D is the diameter of the mitral valve anulus. There was a weak correlation between thermodilution and Doppler measurements of cardiac output (r = 0.64, p less than 0.01), while a good correlation was observed between percent changes in thermodilution-derived cardiac output and those in Doppler-determined cardiac output (r = 0.92, p less than 0.01) during different loading conditions. It has been suggested that this method may be useful for assessing relative changes in cardiac output during short time periods.

Plasminogen activator inhibitor-1 suppresses endogenous fibrinolysis in a canine model of pulmonary embolism

BACKGROUND

Plasminogen activator inhibitor-1 (PAI-1), the specific, fast-acting inhibitor of tissue-type plasminogen activator (t-PA), binds to fibrin and has been found in high concentrations within arterial thrombi. These findings suggest that the localization of PAI-1 to a thrombus protects that same thrombus from fibrinolysis. In this study, clot-bound PAI-1 was assessed for its ability to suppress clot lysis in vivo.

METHODS AND RESULTS

Autologous, canine whole blood clots were formed in the presence of increasing amounts of activated PAI-1 (0-30 micrograms/ml). Approximately 6-8% of the PAI-1 bound to the clots under the experimental conditions. Control and PAI-1-enriched clots containing iodine-125-labeled fibrin (ogen) were homogenized, washed to remove nonbound elements, and delivered to the lungs of anesthetized dogs where the homogenates subsequently underwent lysis by the endogeneous fibrinolytic system. 125I-labeled fibrin degradation products appeared in the blood of control animals within 10 minutes and were maximal by 90 minutes. PAI-1 reduced fibrin degradation product release in a dose-responsive manner at all times between 30 minutes and 5 hours (greater than or equal to 76% inhibition at 30 minutes, PAI-1 greater than or equal to 6 micrograms/ml). PAI-1 also suppressed D-dimer release from clots containing small amounts of human fibrin (ogen). t-PA administration attenuated the effects of PAI-1, whereas latent PAI-1 (20 micrograms/ml) had no effect on clot lysis. Blood levels of PA and PAI activity remained unaltered during these experiments.

CONCLUSIONS

The results indicate that PAI-1 markedly inhibits endogenous fibrinolysis in vivo and, moreover, suggest that the localization of PAI-1 to a forming thrombus is an important physiological mechanism for subsequent thrombus stabilization.

Correlates of cortical bone mass among premenopausal and postmenopausal Japanese women

Few studies have examined the multifactorial risk factors of bone mass in Asian populations. This cross-sectional study was designed to explore relationships between bone mass and environmental variables, including dietary and life-style factors, in Japanese women living in Japan. A total of 178 Japanese women completed the study: 89 premenopausal, ages 35-40, and 89 postmenopausal, ages 55-60. Midradial bone mineral content (MBMC) and bone mineral content per unit area, referred to as bone density (MBMD), were measured using single-photon absorptiometry. The major results of this investigation were the following: (1) The postmenopausal women differed significantly from the premenopausal women in having lower radial bone parameters, lower mean height, later age of menarche, and higher dietary intakes of carbohydrates, vegetables, and milk with a lower intake of caffeine. (2) Current protein intake was a positive correlate of MBMC in both groups. (3) Intake of vegetables (leafy green, yellow, orange, and white) and current milk intake were positively associated with MBMC in the postmenopausal women. (4) For the premenopausal women, irregular menstrual cycles was a negative correlate of MBMC, and for the postmenopausal women, years of menopause was negatively associated with MBMC and MBMD. Longitudinal studies are needed to establish more conclusively associations among diet, life-style, and reproductive history and bone mass of Japanese women.

Interleukin-1 enhances the response of osteoblasts to platelet-derived growth factor through the alpha receptor-specific up-regulation

Both platelet-derived growth factor (PDGF) and interleukin-1 (IL-1) are produced by activated macrophages and are thought to contribute to bone remodeling, but their precise roles remain to be clarified. The interaction between PDGF and IL-1 was, therefore, studied in normal osteoblast-like cells (MC3T3-E1). The expression of alpha- and beta-PDGF receptors on MC3T3-E1 cells was detected by RNA blot analysis and confirmed by immunoblot analysis. PDGF-induced chemotactic as well as mitogenic activities were synergistically enhanced by either IL-1 alpha or IL-1 beta (40 units/ml) pretreatment in serum-free medium, although IL-1 alone did not show any detectable chemotactic activities. This biological enhancement by IL-1 was accompanied by a selective increase of alpha-PDGF receptor expression, following the augmentation of alpha receptor autophosphorylation and inositol phosphate hydrolysis induced by PDGF-AA. These findings suggest that PDGF and IL-1 are jointly involved in the bone-remodeling microenvironment as local coupling factors.

Secondary generalization in kainic acid-induced focal seizures in unanesthetized cats

Seizure propagation was studied with different seizure models induced by a kainic acid (KA) microinjection in nonanesthetized cats. These seizures were characterized with a focal onset of seizures followed by secondarily generalized seizures. The mesencephalic reticular formation (MRF) played an important role when an epileptogenic focus was located in a unilateral amygdala, hippocampus, thalamus or visual cortex. When the focus was located in a unilateral lateral geniculate body, a fast, synchronous and bidirectional propagation was observed in the sensorimotor cortex (SMC) and MRF. Brain stem seizure (generalized tonic seizure) was elicited by the KA injection into MRF. The EEG of generalized seizure was characterized by the propagations of seizure activities of MRF immediately to the bilateral SMC and thalamus. The results suggested that MRF participated actively in the generalization of the KA-induced seizures.

Protein kinase C is involved in PTH-induced homologous desensitization by directly affecting PTH receptor in the osteoblastic osteosarcoma cells

We have investigated mechanisms of PTH-induced homologous desensitization reflected in the refractoriness of cAMP response to the second exposure to PTH in the clonal rat osteosarcoma cell line, UMR-106. Preincubation with 10(-7) M rat (r) PTH-(1-34) for 6 h caused the desensitization, resulting in a 65% decrease in cAMP accumulation in response to further exposure to rPTH. This desensitization was apparent at 10(-10) M rPTH and maximal at 10(-7) M rPTH. UMR-106 cells treated with protein kinase C (PK-C) activating phorbol ester, phorbol 12-myristate 13-acetate (PMA, 10(-6) M) for 6 h also induced desensitization manifested by a loss of rPTH-stimulated cAMP accumulation to 50% of that in the control cells. On the other hand, 4 alpha-phorbol 12,13-didecanoate, incapable of activating PK-C, failed to induce desensitization. Fifty micromolar H-7 (PK-C inhibitor) significantly blocked both rPTH- and PMA-induced desensitization. Thus, PK-C seemed to play a major role in rPTH-induced desensitization. Pretreatment with neither rPTH nor PMA changed the cAMP responsiveness to 10 micrograms/ml cholera toxin or 100 microM forskolin. Islet activating protein failed to influence the desensitization in this cell line. PTH receptor binding, assessed by using 125I-labeled [Nle8,Nle18,Tyr34]PTH-(1-34) as a radioligand, was decreased along with PTH receptor numbers by pretreatment with rPTH or PMA. These data indicate that rPTH-induced homologous desensitization occurs at least in part through the activation of PK-C and that PK-C directly affects PTH receptor in UMR-106 cells.

Effects of RA642, a new central pressor agent, on renal sympathetic nerve activity and blood pressure during hemorrhagic shock in rabbits

This experiment was designed to evaluate effects of RA642, a pyrimido-pyrimidine derivative, on renal nerve activity (RNA), mean blood pressure (MBP), central venous pressure (CVP), and heart rate (HR) during hemorrhagic shock in anesthetized rabbits. Hemorrhagic hypotension of 30 mmHg was induced by rapid bleeding and was controlled by a servocontrolled pump. Following the onset of hemorrhagic hypotension, RNA response showed a triphagic pattern: an initial increase in RNA and a secondary increase followed by a profound decline in RNA. In all animals, decreases in RNA occurred within approximately 30 min after bleeding in association with significant decreases in heart rate. When RNA fell to near noise level, the effects of RA642 (0.25 mg/kg, iv, N = 10), physiological saline (N = 7), epinephrine (10 micrograms/kg, iv, N = 6), and dopamine (10 micrograms/kg, iv, N = 5) were then tested. Intravenous injection of saline produced no significant improvements of hypotension nor of reduction in RNA. However, treatment with RA642 produced a significant increase in MBP simultaneously with an increase in RNA. During the hypovolemic hypotensive phase, tachycardia did not occur after the treatment with RA642. Twenty-five minutes after the retransfusion, MBP and RNA in the RA642-treated group were at significantly higher levels than in the saline group. HR did not significantly change with the RA642 treatment after the retransfusion. In another six animals, when RNA fell to near noise level, epinephrine caused a transient increase in MBP and HR. Ventricular arrythmias occurred in 50% of epinephrine-treated animals. However, the level of MBP as improved by epinephrine was significantly lower than that by RA642 at 25 min after the retransfusion.(ABSTRACT TRUNCATED AT 250 WORDS)

Suppressive effect of 1,25(OH)2D3, and glucocorticoids on production of tumor necrosis factor-alpha by human peripheral blood adherent cells

Effect of 1,25(OH)2D3 and glucocorticoids on production of TNF-alpha by human peripheral blood adherent cells (HPBAC) was investigated. TNF-alpha was measured by ELISA method using monoclonal antibody against human recombinant THF-alpha. Maximal TNF-alpha production by HPBAC was observed in 4 to 8 hr after incubation when these cells were cultured for 24 hr with 10 micrograms/ml lipopolysaccharide (LPS), 10 ng/ml 12-o-tetradecanoyl-phorbol-13-acetate (TPA) and 10(-5) M indomethacin (INDM). When graded concentration of 1,25(OH)2D3 was added to HPBAC in the presence of above stated dose of LPS, TPA and INDM, a significant suppression of TNF-alpha production was first observed at the concentration of 10(-8) M (P less than 0.05). Similar significant suppressive effect was also observed by adding hydrocortisone and dexamethasone at the concentration of 10(-8) M (P less than 0.05) and 10(-7) M (P less than 0.05), respectively. These results may suggest that 1,25(OH)2D3 has the same inhibitory effect on monocyte/macrophage function as glucocorticoids.

[Ectopic salivary amylase-producing IgA- lambda-type multiple myeloma with expression of MDR-1/P-glycoprotein]

We report a case of ectopic salivary amylase-producing IgA- lambda-type multiple myeloma. A 70-year-old man was admitted because of anemia and renal failure. After chemotherapy for eight months, the serum amylase markedly increased. Amylase activity in the supernatant of cultured myeloma cells, which were obtained from the bone marrow, also increased. The myeloma cells expressed MDR-1/P-glycoprotein). The case implies the association of drug resistance and the ectopic amylase production in a case of multiple myeloma.

[Ventriculo-lumbar perfusion chemotherapy with methotrexate and cytosine arabinoside for meningeal dissemination of malignant disease]

Ventriculolumbar perfusion chemotherapy with methotrexate (MTX) and cytosine arabinoside (Ara-C) was performed in six patients with meningeal dissemination of malignant disease. Ten mg of MTX and 40 mg of Ara-C were injected via Ommaya reservoir every 12 hours for 3 days. During perfusion, we observed nausea and vomiting, low grade fever, confusion, nystagmus, paresthesia or numbness of the lower extremities, and multicranial nerve impairment, which disappeared soon after perfusion chemotherapy. After treatment, one patient developed bacterial meningitis, and two developed MTX-induced interstitial pneumonitis, which was cured by steroid therapy. Signs and symptoms due to involvement of the cerebrum, cranial nerves and spinal cord or spinal roots, improved more than by standard intrathecal chemotherapy. Laboratory cerebrospinal fluid (CSF) findings, i.e., cell count and cytological appearance, also improved more than by standard intrathecal chemotherapy. EEG, CT scan and MRI data revealed a worsening of EEG findings in one patient, and a small lesion on MRI, which was not seen by CT scan, disappeared after treatment in two patients.

The activation of cAMP-dependent protein kinase is directly linked to the regulation of osteoblast proliferation (UMR-106) by parathyroid hormone

In order to characterize the direct involvement of cAMP in the change of osteoblast proliferation by parathyroid hormone (PTH), we employed the diastereoisomers of adenosine 3',5'-cyclic phosphorothioate, Sp-cAMPS and Rp-cAMPS, which have been recently shown to act directly as agonist and antagonist, respectively in the activation of cAMP-dependent protein kinase (PKA). Dibutyryl cAMP (dbcAMP) and cholera toxin as well as human(h) PTH-(1-34) significantly inhibited [3H]thymidine incorporation (TdR) in osteoblastic osteosarcoma cells, UMR-106. Sp-cAMPS (10(-6)-10(-4) M) inhibited TdR in a dose-dependent manner. Although Rp-cAMPS (10(-6)-10(-4) M) itself did not affect TdR, it significantly blocked dbcAMP-, cholera toxin- and Sp-cAMPS-induced suppression of TdR. Moreover, Rp-cAMPS (10(-6)-10(-4) M) dose-dependently antagonized hPTH-induced suppression of TdR. Present studies first indicated that the activation of PKA is directly linked to the change of osteoblast proliferation by PTH.

Possible role of sodium-hydrogen antiport in acetylcholine-induced relaxation of rat aorta

The decreased extracellular Na concentration (25mM) attenuated vasodilator effect of acetylcholine (ACh) in norepinephrine-treated aortic ring. This attenuation was greater in the low Na medium substituted by Li, which can exchange intracellular H through Na-H antiport, as compared with that substituted by choline, which cannot. 10 microM amiloride canceled the difference between the two low Na mediums. Thus the inhibition of Na-H antiport may counteract the suppressive effect of decreased intracellular Na on ACh vasodilation, suggesting a possible role of Na-H antiport in a release of vasoactive substance(s) from endothelial cells.

Role of increase in intracellular calcium in PTH-induced homologous desensitization in UMR-106 cells

Effects of increase in intracellular calcium on PTH-induced homologous desensitization were investigated using calcium ionophores. Pretreatment of UMR-106 cells (rat osteoblast like osteosarcoma cell line) with calcium ionophores (A23187 or ionomycin) for 6h resulted in approximately 50% decrease of PTH-stimulated cAMP production. PTH receptor binding, assessed with 125I-[Nle8,Nle18,Tyr34]PTH-(1-34) as radioligand, was significantly decreased in 10(-6) M calcium ionophore-pretreated (for 6h) cells without affecting the dissociation constant (Kd) for PTH. Minimal effective treatment period was 2h and similar inhibitory effect was observed in 12h-treated cells. These data suggest that increase in intracellular calcium might also act on PTH receptor in the similar manner as protein kinase C activation to induce desensitization.

Electron transport inhibition of the cytochrome bc1 complex of rat-liver mitochondria by phenolic uncouplers

The respiration inhibition of rat-liver mitochondria by a series of substituted phenolic uncouplers was studied. The inhibitory effects were classified into three types, I-III, depending on the pattern of the changes in inhibitory potency observed when the potent uncoupler SF6847 was simultaneously applied. The extent of inhibition by type I phenols did not change as the transmembrane potential was dissipated by SF6847, but the extent of inhibition by type II and III phenols was decreased and increased, respectively. With the addition of another potent uncoupler, fluazinam, the uncoupling activity of which disappears with time, the inhibitory potency of type II phenols was decreased, but increased reversibly with the disappearance of the uncoupling effect of fluazinam. However, the inhibitory potency of type III phenols increased by fluazinam was not reduced. The inhibitory site of the phenols studied here was the cytochrome bc1 complex. This complex undergoes conformational changes when the transmembrane potential changes. The findings suggested that inhibition by substituted phenolic uncouplers depends partially on conformational changes of the cytochrome bc1 complex that accompany variations in the transmembrane potential.

[Posterior interosseous nerve paralysis caused by ganglion: a case report]

A 63-year-old man presented with a posterior interosseous nerve palsy secondary to a ganglion compressing the nerve against the arcade of Frohse. Decompression and neurolysis resulted in full functional recovery. While patients with the so-called classic "Saturday night palsy" or even patients with a radial nerve palsy secondary to a fractured humerus may be expected to recover completely without surgery, early surgery is the conservative approach in patients with a nerve palsy secondary to the mass. However it is difficult to diagnose the nerve palsy secondary to the small mass. The treatment for patients with a progressive nerve palsy of unknown origin must be given attention.

Hypotensive action of taurine in DOCA-salt rats--involvement of sympathoadrenal inhibition and endogenous opiate

We studied the roles of the sympathoadrenal system and endogenous opiate in the antihypertensive effects of supplementation of dietary taurine, a sulfur amino acid, in deoxycorticosterone acetate (DOCA)-salt rats. Supplementation of 1% taurine in drinking water for 2 weeks was found to prevent the increase in systolic blood pressure of DOCA-salt rats (116 +/- 2 vs 138 +/- 2 mmHg, p less than 0.01), but failed to effect the systolic blood pressure of vehicle-treated control rats (115 +/- 2 vs 112 +/- 3 mmHg), taurine supplementation restored to normal increased plasma norepinephrine (326 +/- 32 vs 531 +/- 67 pg/ml, p less than 0.01) and epinephrine (204 +/- 19 vs 304 +/- 43 pg/ml, p less than 0.05) concentrations in DOCA-salt rats, but had no effect on norepinephrine (346 +/- 23 vs 338 +/- 33 pg/ml) or epinephrine (198 +/- 17 vs 224 +/- 26 pg/ml) concentrations in control rats. Accordingly, the increased epinephrine content in the adrenals of DOCA-salt rats was normalized with the supplementation of taurine, associated with a markedly increased adrenal taurine content. In conscious rats, moreover, intraperitoneal injection of naloxone (2 mg/kg), a specific opiate antagonist, increased systolic blood pressure only in taurine-supplemented DOCA-salt rats. Evidence presented suggests, therefore, that both the suppression of the increased sympathoadrenal activity and the activation of endogenous opiate might contribute to the antihypertensive effect of taurine in DOCA-salt rats.

Taste cells in the gut and on the tongue. Their common, paraneuronal features

Chemoreception of foodstuff in the gut is performed by endocrine cells dispersed in the gut epithelium. They are bipolar cells extending an apical process to the gut lumen and releasing their messenger substances from the cell base in response to the apical stimuli. The cells share cell-biological features with neurons and are classified as paraneurons. Noteworthy, the gut paraneurons do not seem to be stimulated by monosodium glutamate (MSG) as our dog experiment indicates. Administration of 50 mM MSG into the duodenal loop of anesthetized dogs did not cause changes in the volume and protein output in the pancreatic juice. The gustatory cells in the taste bud show essentially the same structure and function as the gut endocrine cells. A single gustatory cell type (type III) seems to receive different chemical stimuli, whereas different endocrine cell types in the gut react to different stimuli. The gustatory cells possess numerous peptidergic-type granules besides synapse-associated small clear vesicles. The former granules, in the guinea pig and dog, are abundant in the cytoplasm, giving an endocrine-like appearance to the cell. Peptidic signal substances contained in the granules remain to be identified. Comparison of the gustatory cells in the taste bud with the endocrine cells in the gut and with other paraneurons may put into front certain hitherto unexplored structures and functions of the cells.