Fluorescent localization of catecholamine stores in the rat lung

Abstract

To localize the stores of catecholamines present, normal rat lungs were examined with a histochemical fluorescence technique. Comparison was made with sections from animals infused with methylene blue to demonstrate the autonomic innervation usually observed. A n extensive network of fine fluorescent fibers was seen in the mucosa of the entire bronchial tree. Coarse interstitial fibers adjacent to bronchi represented the largest monoamine stores observed, and communicated by delicate fibers with both the musculature and mucosa. Arterial fluorescence was less prominent, and a continuous subendothelial layer of coarse fluorescent material communicated with finer fibers in the muscular walls. The extensive fluorescent fibrous network visualized with the present method, demonstrating fine details of innervation, suggested a n intimate relation between the bronchi and pulmonary arteries.Catecholamines in a dry protein layer exposed to formaldehyde gas are transformed into products with an intense green to yellow-green fluorescence (Falck et al., '62). This reaction has been studied with the use of model systems, and its chemical specificity reported (Corrodi and Hillarp, '63, '64). This method has been utilized for the cellular localization of monoamines in the adrenal medulla (Falck and Torp, '61), brain (Dahlstrom and Fuxe, '64) and adrenergic fibers in various organs and tissues (Angelakos et al., '63). Because of the relatively high concentration of norepinephrine in sympathetic nerve terminals the adrenergic innervation can be readily visualized. In kidney the specific fluorescence is seen only in relation to blood vessels (Nilsson, '65) similar to the vasomotor nerve localization observed in other tissues.Knowledge of the catecholamines stored in the lung may help explain alterations involving the blood vessels and bronchi that often are interpreted as disturbances of the autonomic nervous system. The pulmonary vascular alterations associated with cardiovascular disease are well known morphologically (Hinke, '65) although the arteries of the lung are thought to play a passive role in their development. Increased catecholamine metabolism in congestive heart failure associated with valvular heart lesions where pulmonary ANAT. REC., 156: 19-30.arteriosclerosis is a prominent feature is felt to demonstrate augmented activity of the sympathetic nervous system (Chidsey et al., '65).Experiments with isolated perfused lungs and isolated pulmonary vessels have played a large part in the examination of these reactions (Daly, '61 ). The perfusion technique, of necessity, is abnormal and the lung vessels are consequently less reactive than they are in the intact animal. The present report describes histochemical findings in rapidly processed normal rat lungs. Basic pulmonary pathologic alterations may be interpreted differently with understanding of the finer details of pulmonary innervation and appreciation of monoamine metabolites present. MATERIALS AND METHODSFemale albino rats weighing 100-150 gm were kept...

Characterization of endogenous noradrenaline release from intact and epithelium‐denuded rat isolated trachea

“…Removal of the epithelium was accompanied by a significant reduction of the NA tissue levels (about 30%), indicating that some of the sympathetic fibres may terminate in the epithelium. This is supported by observations from fluorescence histochemical studies (Zussman, 1966). However, removal of the epithelium resulted also in a marked reduction of the release of NA from the remaining nerve endings as indicated by the pronounced fall in the fractional release of NA (Table 2).…”

“…A possible role of the epithelium in the regulation of NA release was investigated, since there is increasing evidence that the airway epithelium plays an important part in the regulation of the airway smooth muscle tone (see Goldie et al, 1990) and has pronounced inhibitory effects on the release of acetylcholine (Wessler et al, 1990a,b). Preliminary accounts of the present results have been given (Rack6 et al, 1989a;1990).…”

Catecholamine Transport in Isolated Lung Parenchyma of Pig

“…Platelets and mast cells have previously been discounted as likely sites of [3H]-NA accumulation (Junod & Ody, 1977). It is most unlikely that noradrenergic nerves were involved in the accumulation of any of these catecholamines, since sympathetic innervation of airways smooth muscle is sparse or absent below the level of the bronchi in rat (Zussman, 1966;El-Bermani, 1978), guinea-pig (O'Donnell, Saar & Wood, 1978, rabbit and pig lung (Mann, 1971), leaving only the sparse innervation of the most peripheral pulmonary blood vessels. Thus it is likely that [3H]-NA was transported primarily into capillary endothelium in incubated lung strips as it was in perfused lung (Hughes, Gillis & Bloom, 1969;Gillis, 1976) where cocaine and imipramine were potent uptake inhibitors (Iwasawa & Gillis, 1974;Nicholas et al, 1974), while [3H]-Iso was largely transported by a different process.…”

“…B6nisch, Uhlig & Trendelenburg, 1974) and in kitten isolated coronary arteries (Cornish & Goldie, 1980 (Iwasawa, Gillis & Aghajanian, 1973) and rat lung (Nicholas, Strum, Angelo & Junod, 1974) (Junod & Ody, 1977). It is most unlikely that noradrenergic nerves were involved in the accumulation of any of these catecholamines, since sympathetic innervation of airways smooth muscle is sparse or absent below the level of the bronchi in rat (Zussman, 1966;El-Bermani, 1978), guinea-pig (O'Donnell, Saar & Wood, 1978, rabbit and pig lung (Mann, (Hughes, Gillis & Bloom, 1969;Gillis, 1976) where cocaine and imipramine were potent uptake inhibitors (Iwasawa & Gillis, 1974;Nicholas et al, 1974) (Bakhle & Vane, 1974;Gillis & Roth, 1976;Sole et al, 1979) or in vitro (Gillis, 1976 (Bassett, 1971;Picken & Jarrott, 1975;Brine, Cornish & Miller, 1979). Cocaine (10 uM) and desipramine (1 pM), which did not significantly alter the cellular accumulation of radioactivity from [3H]-Iso, also failed to alter significantly the Iso concentrationeffect curves.…”

Pulmonary noradrenergic innervation of rat and monkey: a comparative study

“…These studies have uniformly shown adrenergic nerves to be concentrated at the adventitio-medial junction (for example, Falck (1962) ;Fuxe and Sedvall (1965); Ehinger et al (1967)). The few studies of pulmonary vascular nerves have also shown nerve terminals mainly in the adventitial layer (Altenahr, 1965;Zussman, 1966;tech and Dolezel, 1967;Fillenz, 1967). Some authors have noted a dearth of vascular innervation, and controversy has arisen regarding the distribution of various types of nerves (tech and Dolelel, 1967;tech, 1969).…”