Lars Malm

Substance-P-containing nerve fibers in the nasal mucosa.

SummaryNerve fibers displaying SP immunoreactivity were detected in the nasal mucosa of several mammals. The fibers were seen around small blood vessels, seromucous glands, and beneath and sometimes within the surface epithelium. In the pterygopalatine ganglion and the trigeminal ganglion, known to innervate the nasal mucosa, SP-positive nerve cell bodies were seen. Sympathetic denervation with 6-hydroxydopamine (6-OHDA) or bilateral cervical sympathectomy did not visibly affect the distribution of SP fibers in the nasal mucosa in mice or rats. The findings are compatible with the view that the bulk of SP fibers to the nasal mucosa derive from the trigeminal ganglion with a possible contribution from the pterygopalatine ganglion.

The Origin of Vasoactive Intestinal Polypeptide (VIP) Nerves in the Feline Nasal Mucosa

The feline nasal mucosa is richly supplied with vasoactive intestinal polypeptide (VIP) immunoreactive nerve fibres. The nerves occur in the subepithelial connective tissue, around small blood vessels and around the acini of seromucous glands. The ptergopalatine ganglion contains numerous VIP immunoreactive nerve cell bodies among non-reactive ones. Extirpation of the ganglion results in an almost complete disappearance of VIP-containing nerves in the nasal mucosa, while sectioning of the preganglionic nerve (Vidian nerve) does not affect the number of nasal VIP nerves. Hence the bulk of VIP nerve fibers in the nasal mucosa derive from cell bodies located in the pterygopalatine ganglion.

Effects of vasoactive intestinal polypeptide on resistance and capacitance vessels in the nasal mucosa.

Vasoactive intestinal polypeptide (VIP) immunoreactive nerves have previously been demonstrated in the feline nasal mucosa. In the present investigation it is shown that VIP given close arterially dilates both resistance and capacitance vessels in the nose of the cat. This vasodilatation is atropine resistant. It is suggested that VIP serves a physiological role in the neurogenic control of blood vessels in the nasal mucosa.

Pharmacological Background to Decongesting and Anti-inflammatory Treatment of Rhinitis and Sinusitis

A review is given of the literature concerning effects of oral and topical decongestants and anti-inflammatory drugs in rhinitis and sinusitis. Oral vasoconstrictors, effective in decongesting the nasal mucosa, need to be taken in doses that may induce disturbing systemic side-effects. Nonsteroidal anti-inflammatory drugs (NSAIDs) have weak effects in allergic rhinitis as compared with glucocorticosteroids. No controlled clinical trials of systemic glucocorticosteroids in sinusitis have been published. Four studies in which different glucocorticosteroids were administered topically for sinusitis have been performed, but these gave very weak support for any positive effects of such a treatment.

Sympathetic Influence on the Nasal Mucosa

The tone of the resistance vessels determines the capillary flow and the tone of the capacitance vessels --the nasal patency. Lower impulse frequencies in the sympathetic nerves affect mainly the capacitance vessels, while higher frequencies affect both types of vessel. The existence of both alpha- and beta-adrenoreceptors and their distribution offer pharmacological ways to affect mainly one type of the vessels.

Use of pharmacologic decongestion in the generation of rhinomanometric norms for the nasal airway

It has been reported that nasal decongestion can be more effectively achieved by regulated exercise than by the use of decongestant nose drops. To test this finding, we assessed the relative effectiveness of physical exercise, nose drops, and sprays on 100 consecutive patients with nasal congestion. We found that decongestion was best achieved by spraying the nasal mucosa twice, seven to eight minutes apart, with 0.1% xylometazoline solution (Otrivin; Ciba-Geigy). This study demonstrates that rhinomanometric improvement correlates well with subjective improvement following septoplasty. Rhinomanometric limits for the selection of patients suitable for functional operations of the septum or lateral walls of the nose are presented.

Isoprenaline-induced facilitation of the Eustachian tube opening

Isoprenaline was given i.v. to rats and its ability to change the air pressure necessary to open the Eustachian tube (ET) was studied. Air was injected once a minute into the middle ear via a tube glued to a hole in the tympanic bulla. The rate of pressure increase was 0.7 kPa/sec. The air pressure at which the ET opened was in 10 rats 3.4 +/- 0.3 (SE) kPa. Isoprenaline in a dose of 1 microgram/kg decreased this pressure opening level (Pol) by 0.14 +/- 0.03 kPa and with 10 micrograms/kg by 0.22 +/- 0.03 kPa. These effects were reduced by propranolol. Isoprenaline did not act via released adrenaline. A surface tension lowering substance, Tween 20, instilled into the middle ear, decreased Pol by about 0.9 kPa. It is suggested that isoprenaline evokes a decreased Pol via secretion of surface tension lowering substances.

Vip Increases in Nasal Blood During Stimulation of the Vidian Nerve

In chronically sympathectomized cats Vidian nerve stimulation evoked vasodilatation concomitant with an increase of VIP concentration in venous plasma effluent from the nasal mucosa. the VIP increase and the vasodilatation was not affected by atropine administration, but abolished by hexamethonium. It is suggested that neuronal VIP may be the mediator of the atropine-resistant vasodilatation.

Effect of atropine on the eustachian tube function.

The effect of atropine on the eustachian tube function was studied by means of a recently designed method. The results out of 20 examined ears showed that atropine significantly reduced both active and passive functions of the eustachian tube. The findings are discussed and it is concluded that the method used might be a valuable tool in forthcoming studies of pharmacological effects on the eustachian tube function.

Selection with and without Rhinomanometry of Patients for Septoplasty

One hundred and fifty-two patients were selected for septoplasty on the basis of symptoms and clinical examination, but without the aid of rhinomanometry. The patients were reexamined at a mean of 3.5 years later when rhinomanometry was included. On the second occasion, in 30% of the patients nasal airway resistance (NAR) of the narrower cavity after decongestion was lower than the upper 95% prediction limit of NAR of individuals with no nasal complaints, and in 18% NAR was lower than the mean NAR + 1 SD for the same individuals. At reexamination of the patients who had not yet undergone operations, about a quarter of those with a “normal” NAR no longer had any subjective obstruction. It is concluded that rhinomanometry is of value in selecting patients for septoplasty.